Objective To investigate the roles of TLR3 pathway activiated by polyI:C in proliferation and apoptosis of multiple myeloma (MM) RPMI8226 cell line.Methods RPMI8226 cells were cultured in RPMI 1640 with different dose of polyl:C.Cells were collected in different time.Proliferation and apoptosis were detected by CCK-8 kit and flow cytometry,separately.Results The proliferation of RPM18226 was inhibited by polyI:C,and it was dose and time dependent,24 h:12.30％ ±2.04％,22.50％±2.20％,37.90％ ±1.30％ ; 48 h:17.80％ ±1.52％,29.60％ ±0.85％,45.80％ ±1.68％ ;72 h:25.10％±1.01％,34.60％±1.27％,60.50％±2.08％,P＜0.05.RPMI8226 cells were incubated with 50 μg/ml,100 μg/ml and 200 μg/ml polyI:C for 48 h.Apoptotic rate were 5.60％ ±1.06％,8.71％ ±1.06％ and 13.93％ ±1.17％,P＜0.05.TLR3 and TRIF mRNA expression increased obviously and dose dependent,TLR3:1.41±0.10,2.24±0.16,4.08±0.13; TRIF:1.07±0.16,1.97±0.13,3.56±0.19,P＜0.05.Conclusion The proliferation of MM cells were inhibited by TLR3 pathway obviously,and apoptosis was induced by polyI:C.