OBJECTIVE： To investigate the compatibility stability of Ulinastatin for injection with 2 commonly used solvents in the infusion pump. METHODS： After Ulinastatin for injection 500 000 U was respectively added into 0.9％ Sodium chloride injection and 5％ Glucose injection 50 mL， the appearance of the mixture at 25 ℃， 37 ℃ were observed at 0，1，2，4，8，12，24 h， respctively. pH value and the number of insoluble particles were measured. The relative percentage of ulinastatin in the mixture was determined by HPGFC. RESULTS： Under this condition， the appearance and pH value of the mixture had no significant change within 24 h； the number of particles ≥10 μm was lower than 25 particle/mL， and that ≥25 μm was lower than 3 particle/mL， which was in line with the pharmacopeia standard. The relative percentage of ulinastatin within 24 h ranged 99.45％-102.55％. CONCLUSIONS： After mixed with 0.9％ Sodium chloride injection and 5％ Glucose injection， Ulinastatin for injection keep stable within 24 h at 25 ℃， 37 ℃ and can be used for continuous administration in the infusion pump.