Objective To examine the clinical efficacy of two types of venous indwelling needle on aged cor pulmonary patients.Methods 60 aged cor pulmonary patients were randomly divided into two groups,thirty patients in control group with BD-22G venous indwelling needle and the rest were in observation group with BD-24G venous indwelling needle,the success rate of venipuncture,phlebitis,catheter blocking and indwelling time were compared between two groups.Results In observation group,twenty nine patients were successful at once venipuncture(96.67%),one patient got phlebitis(3.33%),while in control group there were only nineteen patients were successful at once venipuncture(63.33%),four patients got phlebitis(13.33%),the pain in observation group patients was significantly lower than control group(P0.05),there was no differences between two groups on catheter blocking rates(P0.05).Conclusion BD-24G venous indwelling needle is more suitable for aged cor pulmonary patients than BD-22G venous indwelling needle.