Objective To evaluate the effect of the different methods of PTBD on immunity to treat the patients with the malignant obstructive jaundice throught this prospective clinical control study. Methods There are 91 consecutive cases with the malignant objective jaundice (M:F=57:34), mean age (60.4±11.6 years) who were selected by our standard were accepted PTBD therapy from 2006.3 to 2007.2. The patients who undergo PTIEBD will be send into three group at random: group IED-A(turn off drainage for 2 hours after each meal) 20 cases, group IED-B(turn off drainage duaring daytime) 20 cases, group IED-C(turn off drainage persistently) 15 cases. Thirty-six patients underwent PTIEBD. TC, TH, TS, TH/TS, IgG, IgA, IgM before operation and 2-4 days, 8-10 days, and 1 month after the operation were analyzed by ANOVA test. Results There is no obvious difference in TC, TH, TS, TH/TS, IgG, IgA, IgM among these groups before operation(P>0.05). At 1 month after PTBD, the level of TC, TH, TH/TS: group IED-B>group IEDA>group ED, and the difference between three group is obvious(P<0.05); the level of IgG, IgA: group ED>group IEDA>group IED-B, and comparing group ED with group IED-B, the difference is obvious(P<0.05). At 1 month after PTBD, the level of TC, TH, TH/TS, IgG, IgA has been improved in group IED-A and group IED-B obviously(P<0.05). TC, TH, TH/TS, IgG, IgA did not change obviously after operation in IED-C group(P>0.05). Conclusion The immunity can be improved in group IED-A,B obviously, and group IED-B is better than group IED-A. In group ED and group IED-C, the immunity cann’t be improved obviously.