Papillary function in cholecystolithiasis patients was examined by intraoperative biliary manometry using a new balloon catheter. Pressure measurement was performed in each patient with the balloon deflated and inflated. When the balloon was inflated, the influence of the volume and compliance of the biliary tree was minimized to yield a precise evaluation of papillary function. From our analysis, resting pressure, residual pressure, onset time, and recovery time proved to be influenced by the volume and compliance of the biliary tree. Therefore, these four parameters could not reflect the papillary function exactly. On the other hand, perfusion pressure was not affected by the volume and compliance of the biliary tree. Perfusion pressure was thought to be generated by the resistance of the choledochal outlet and reflect the papillary function. In this study, our balloon catheter proved to be very useful in minimizing the influence of the volume and compliance of the biliary tree. And it is concluded that perfusion pressure is the best parameter to evaluate the resistance of the sphincter of Oddi or papillary function.