Objective To investigate the feasibility and safety of helix hydro-jet lithotrity in treatment of calculus of intrahepatic duct and to establish its basic parameters.Methods The parameter of hydro-jet Was set at different levels of pressure(5000-9000 kPa)and different nozzle directions,and the effect of different parameter wag observed and analyzed in three groups.including 32 ex vivo intrahapatic gallstones.thirty-two ex vivo swine bile ducts and 31 ex vivo bile ducts obtained from patients with hepatolithiasis.Results Lithotrity was successful in all groups with a jet pressure of 5000-9000 kPa.The multiple regression analysis showed that the time of procedure depended linearly on the minimal stone diameter,stone weight andjet pressure.The time of procedure and the time needed to damage the bile duct decreased with the increase in jet pressure.At same jet pressure,the smaller the angle between nozzle and bile duct,the longer the time needed to cause damage in bile duct.The technique was successfully performed in 60 patients,with no severe complications,including bile duct injury.Conclusion It is feasible to treat hepatolithiasis with hydro-jet lithotrity.The most optimal operation condition was hydro-jet pressure of 6000-7500 kPa and frequency of 1 Hz.