关键词: 流动人口, 抽样框, 重复抽选及抽选后合并, 目标总体与抽样总体的关系, 事后加权

Abstract: This paper describes and discusses issues on the establishment of sampling frame，replicate selection and linking after selection，the relation between target population and frame population in migrants surveys. Experience shows that when preparing the sampling frame of migrants surveys，researchers
not only need the support of relevant database，but also should pay particular attention to the effects of accidental factors. For oversized or undersized sample units，a relatively simple approach is to replicate selection，or link sample units after selection. In addition，in a survey whose target population
is the“Registered-household Population”，the relation between target population and frame population in specific areas will appear as“one-to-many”as a result of impacts of cross-border migrant outflows.Thus，post-weighting is necessary when processing data. To ensure the effectiveness of the postweighting，the characteristics of population flows in different provinces should be taken into account，especially the size of floating population both across and within province in the survey sample. Data processing of 2013 National Fertility Desires Survey indicates that the grouping variables and number of groups of post-weighting in different provinces are not exactly the same，but subject to some flexibility.

Keywords: Migrants, Sampling Frame, Replicating Selection and Linking after Selection, Relation between Target Population and Frame Population, Post-weighting