In the present study, we adopted real-time ultrasonography to investigate the effect of atropine on the gallbladder emptying induced by CCK-OP in the normal subjects, and the difference of gallbladder emptying induced by CCK-OP between the "silent" gallstone patients and the controls. The results showed that: (a) CCK-induced gallbladder emptying in normal subjects was inhibited from 88.7% +/- 5.5% without atropine to 43.4% +/- 9.4% with atropine (P < 0.001). (b) The fasting gallbladder volume in the "silent" gallstone patients (26.7 +/- 10.9cm3) was significantly larger than that in the control (19.2 +/- 7.3cm3) (P < 0.05) and gallbladder emptying in the "silent" gallstones patients (44.0% +/- 8.7%) was significantly lower than that in the control (53.4% +/- 6.4%) (P < 0.01). We concluded that, significantly inhibited CCK-induced gallbladder emptying and there was significantly impaired gallbladder emptying in the patients with gallstones.