Abstract: Statistical analyses on initial contamination of 624 disposal medical infusion items have been made. The normal distribution of the initial contamination, the relation of initial contamination on inner and outer walls of disposal medical infusion items and the changes of initial contamination before irradiation are shown. The sterilizated dose for disposal infusion is determined as 17.2 kGy using bioburden information. The SAL (sterility assurance level) dose is 10~6. The SIP (device sample item proportion) is 1 and the average initial contamination is 7 CFU/item.