Objective: To provide evidence for three-level prevention of cholelithiasis by means of observing the effects of some choleretics on bile compositions drained from patients with pigment gallstone.Methods: Twenty-seven patients suffering from primary pigment gallstones and having received treatment of choledochostomies plus T-tube or endoscopic nasal bile drainage (ENBD) were divided equally into three UDA group) and combination of LDL and UDA (the LDL+ UDA group) through oral intake(7 patients in each group). Besides, 6 post-operational patients got no treatment with any drug were allocated in the control group. Bile of all the patients was collected before treatment and on the 1, 3, 5, 7th day after the treatment started to detect levels of total bile acid (TBA), glycocholic acid (GCA), taurocholic acid (TCA), glycocholic cheno-desoxycholic acid (GCDCA), total bilirubin (TBIL), uncombined bilirubin (UCB), concentration of calcium ion (Ca2+ ) as well as the bacterio-genetic and endogenous β-glucuronidase activity for comparing.Results: Levels of TBA, GCA, TCA and GCDCA got gradually increased in the UDA group and the LDL+ UDA group after treatment ( P＜0.05), while those in the LDL group remained unchanged, showing an insignificant difference as compared with those in the control group. In the LDL group and the LDL + UDA group, TBIL gradually increased while UCB gradually decreased in the course of treatment ( P＜0.05). Moreover, levels of Ca2+ and endogenous β-glucuronidase activity got significantly lowered (P＜0.05). Conclusion: Combined use of LDL and UDA could elevate levels of TBA, GCA, TCA, GCDCA, enhance the excretion of TBIL in patients with pigment gallstone after bile drainage, lower levels of UCB and Ca2+ and the activity of endogenous β-glucuronidase in the bile, so as to reduce the possibility of stone formation of bile, and therefore, it could be used to prevent the production of pigment gallstone, especially to prevent post-operative recurrence of stones.