Abstract: The long form and short form technique of census forms was applied in 2000 Population Census, and the data of long form of census were obtained by sampling methods. The sampling errors of the long form of Langfang City of Hebei Province and Kashi District of Xinjiang Urgnr Autonomous Region were analyzed by the paper, The sampling method was proved to be scientific and valid. The results of the paper is helpful to understand the long form data of 2000 Population Census, scientifically, and to apply the data correctly. The evaluation conclusions for long form sampling method is of reference value for the sampiing design of population survey.