Stocks are included in determination of the optimal portfolio along with the proportion of each stock and to know how much portfolio return and risk investors will get in the future. The study was conducted on the IDX30 Index on the IDX for the period August 2016 - January 2018. The population of this study used shares that were incorporated in IDX30 Index with sample used was 25 IDX30 Index stocks during the study period. The study uses the optimal portfolio model, namely the Single Index Model The results of the study show that from 25 stocks there are 8 stocks that can form an optimal portfolio with their respective proportions, consisting shares of ADRO, BBC, BBNI, BBRI, BMRI, GGRM, PWON, and UNTR. These shares provide a portfolio expected return of 3.25 percent with a portfolio risk level of 0.07 percent. Keywords: Stock Investment, Return, Risk, Optimal Portfolio, Single Index Model