The study aims to assess a performance of foreign direct investments and their role on Libyan economic growth during the period (1986 -2016) , as well as knowing factors and obstacles in attracting these investments . Results of estimations show that they are consistent with the economic theory . Moreover, its important role on economic growth , even its small size , with a positive effect as evidenced by the results of the tests of the variables . Augmented Dickey Fuller Test and Phillips - Perron Test show that all variables are stationary at 1st difference , in addition, Bounds Test shows that there is a positive long-run relationship between foreign direct investment and economic growth in the Libyan economy , and an error correction model ( ECM ) shows that foreign direct investment contributes to growth In the long-run and the short-run.