This study aims to determine the effect of payment methods Cash On Delivery, Free Shipping and flash sales on Purchase Decisions at Shopee . This type of research is associative with quantitative and qualitative data types. The sampling technique used in this study was purposive sampling. Determining the number of sample members in this study used the roscoe formula and obtained the results of 60 student respondents from STIE AMM Mataram. The analytical method used in this study is multiple linear regression analysis. The test results show that Y = 3.134 + 0.350XI + 0.433X2 + 0.470X3 + e. Partially the variable cash on delivery (COD) with a significance of 0.004 <0.05, free shipping with a significance of 0.000 <0.05 and flash sales with a significance of 0.000 <0.05 indicates that cash on delivery, free shipping and flash sales have an effect significant to the purchase decision at Shopee. Simultaneously the variables cash on delivery (COD), free shipping and flash sales with a significance value of 0.009 <0.05 indicate a significant effect on purchasing decisions at Shopee. Based on the results of multiple linear regression analysis tests, the highest coefficient value was obtained for the flash sale variable of 0.406 and also a tcount of 4.097, indicating that flash sales have a dominant effect on purchasing decisions at Shopee