Abstract: Objective Analyzed the different varieties of purified protein derivative(PPD) used in screening of tuberculosis for tuberculosis close contacts in school, providing reference for school TB screening.Methods According to the sequences of tuberculosis cases found in school, purified protein derivative bacillus Calmette-Guérin(BCG-PPD) and purified protein derivative of tuberculin(TB-PPD) tests for tuberculosis close contacts were carried out respectively in 11 and 5 schools(1098 cases).The results were observed after 72 hours. Skin induration ≥5 mm is positive, ≥15 mm or partially blisters, necrosis, lymphangitis were strongly positive, <5 mm were negative. The difference between the resistant rates was compared with χ² test, and the significance level was set at P<0.05.Results 846 contacts had received BCG-PPD test, 574 were positive with positive rate of 67.85%; 178 were strong positive with the strong positive rate of 21.04%, 94 were negative with the negative rate of 11.11%.; 2 cases of active pulmonary tuberculosis were detected in Strong positive students, with the detection rate of 1.12%. 252 contacts had accepted TB-PPD test, 68 were positive with the positive rate of 26.98%; 13 were strong positive with the strong positive rate of 5.16%, 171 were negative with the negative rate of 67.86%.; 1 cases of active pulmonary tuberculosis were detected in strong positive students with the detection rate of 7.69%. Result rates of the two groups had significant statistical differences (The positive rate, positive rate and the negative rate of χ²=133.53, 34.08, 341.47, P<0.05). The detection rate of active pulmonary tuberculosis among strong positive population were not statistically significant different(χ²=0.47,P>0.05).Conclusion Different reagents for PPD test results varied, In school TB close contacts screening, PPD selection should from the perspective of preventing the undetected TB patients.