Abstract： Objective To evaluate the expression of KAII (CD82) gene inhibited by small interfering RNA (siRNA) in human pancreatic cancer cell line T3. Methods Four sequences of siRNA including A, B,C, D were designed, which were based on the KAI1 gene sequence using online RNA interfering designing software and lentivirus vector was built. Then they were used to transfect T3 cells by liposome 2000 and virus titer was determined. Empty vector containing siRNAd1 lentivrus particle ( MOI =5) was also used to infect T3 cells. The expression of CD82 mRNA was detected by real-time PCR. Results The expression of CD82 mRNA in normal control group, empty vector group, A group, B group, C group, D group were 1. 398 ±0.242,1. 311±0.048, 0. 664 + 0. 093, 0. 345 ± 0. 032, 0. 641 ± 0. 049 and 0. 147 ± 0. 049, respectively, the difference between the expression of CD82 mRNA in empty vector group and that of A, B, C, D groups was significant (P＜0.01 ). Conclusions RNAi was able to inhibit the expression of KAI1 gene CD82 in human pancreatic cancer cell line T3.