Survey methodology and definitions

Appendix 1 Survey methodology

1 Telephone survey

1.1 Survey population

Residents of China aged six and above with access to a residential fixed-line telephone (household or dormitory telephone) or a mobile phone.

Sample coverage

The survey sample covered all 31 provinces, autonomous regions and municipalities in mainland China, excluding Hong Kong, Macao and Taiwan.

Survey population subdivisions

The survey population was divided as follows:

Subpopulation A: people covered by residential fixed-line telephones, including residents with household fixed-line telephones, users of student dormitory telephones and users of other dormitory telephones.

Subpopulation B: people covered by mobile phones.

Subpopulation C: people covered by both mobile phones and residential fixed-line telephones. The overlap between A and B forms subpopulation C; C is the intersection of A and B.

1.2 Sampling method

The China Internet Network Information Center (CNNIC) surveyed subpopulations A, B and C. To maximise coverage of internet users, it used a dual-frame sampling approach. The first sampling frame was a list of residential fixed-line telephone numbers, used to survey subpopulation A. The second was a list of mobile telephone numbers, used to survey subpopulation B.

For the population covered by fixed-line telephones, stratified two-stage sampling was used. To ensure sufficient representativeness, mainland China was divided into 31 strata corresponding to its provinces, autonomous regions and municipalities. Samples were drawn independently within each stratum.

Within each province, samples were allocated on a self-weighting basis. The sample size for each city or prefecture, including its districts and counties, was proportional to its population aged six and above covered by residential fixed-line telephones as a share of the total covered population in the province.

Sampling for the population covered by mobile phones was similar to that for the fixed-line population. Mainland China was again divided into 31 strata by province, autonomous region and municipality, with samples drawn independently in each. Within each province, samples were allocated according to each city's share of the resident population to achieve a self-weighting allocation.

Telephone numbers were selected using the following procedure to give each number within a city or prefecture an approximately equal chance of selection, give prefixes containing more telephone numbers a greater probability of selection, and keep fieldwork practicable.

For mobile-phone interviews, all mobile-number prefixes in each city or prefecture were included. Based on the required valid sample size, a quantity of four-digit random numbers was generated and combined with the local mobile prefixes to form a number database (prefix plus four random digits). The database was randomly ordered, and interviews were attempted by dialling the numbers in that order. Fixed-line sampling similarly combined random digits with telephone prefixes and called the resulting numbers. To avoid duplicate sampling, only residential fixed-line telephones were interviewed in that part of the survey.

Internet-user totals were estimated using multivariate joint weighting based on the latest population characteristics published by provincial statistical bureaux. The published population figures were estimates derived from annual census data or annual population sample surveys. This report used them to adjust the weights for the half-yearly survey, disregarding differences between survey periods.

1.3 Sampling error

Calculations based on the sampling design indicate that, for proportion estimates in the individual internet-user survey, such as internet penetration, the maximum permissible absolute error at a 95% confidence level was 0.64 percentage points. Error ranges for other estimates, such as internet-user totals, can be derived from this.

1.4 Survey mode

The survey was conducted using a computer-assisted telephone interviewing system (CATI).

1.5 Differences between the survey population and target population

CNNIC studied people without telephone coverage at the end of 2005 and found very few internet users in that group. As China's telecommunications industry developed, the size of the group gradually declined. This survey therefore assumes that, for the purposes of these statistics, internet users outside both fixed-line and mobile-phone coverage can be disregarded.

2 Definitions used in the report

Internet users: residents of China aged six and above who used the internet during the preceding six months.

Mobile internet users: internet users who accessed and used the internet through a mobile phone during the preceding six months.

Computer internet users: internet users who accessed and used the internet through a computer during the preceding six months.

Rural internet users: internet users who mainly lived in rural China during the preceding six months.

Urban internet users: internet users who mainly lived in urban China during the preceding six months.

IP addresses: addresses that identify internet-connected computers, servers or other network devices. They are a basic internet resource. An IP address, in whatever form, is required to connect to the internet.

Websites: web sites addressed by a domain name itself or by "WWW." followed by that domain name, where the domain registrant is located in China. This includes sites under China's country-code top-level domains .CN and .中国 and traditional generic top-level domains (gTLDs). For example, CNNIC.CN represents one website, reached through CNNIC.CN or WWW.CNNIC.CN. Other addresses ending in that domain, such as WHOIS.CNNIC.CN and MAIL.CNNIC.CN, are treated only as different channels within that website.

Survey scope: unless explicitly stated otherwise, the report's data refer to mainland China and exclude Hong Kong, Macao and Taiwan.

Data cut-off: December 2025.

Data presentation: most figures in the report are approximate values rounded to the stated number of significant digits.

Source: CNNIC, The 57th Statistical Report on China's Internet Development, Appendix I, PDF pages 73-75 (printed pages 65-67). Unofficial English translation.

57th report · December 2025 data · Appendix 1 · V1.0