本文应用了PPS法的两种容量调查“四苗”覆盖率。结果发现,用PPS的小容量法在数万人口的范围内(相当于一个乡的编制,或一个大型企业单位)进行“四苗”接种率考核,抽15个点,每个点抽7名适龄儿童,既能节省人力、物力、时间,又能真实地反映“四苗”的接种情况。认为此法可以在乡级的“四苗”接种率考核中应用。按照EPI的要求,在应用PPS法进行调查时,其结果的95％可信程度的误差不宜超 In this paper, two capacity surveys using the PPS method, “four seedlings” coverage rate. The results showed that PPS small capacity method within the scope of tens of thousands of people (equivalent to a rural establishment, or a large enterprise unit) for “four seedlings” vaccination rate test, pumping 15 points, each pumping seven points School-age children, both to save manpower, material and time, but also a true reflection of the “four Miao” vaccination. Think this method can be used in the township “four seedlings” vaccination rate assessment. According to the requirements of the EPI, when the PPS method is used for investigation, the error of the 95% confidence level of the result should not be exceeded