This paper is to investigate the impact of public investment and FDI on GDP growth of Bangladesh. The Gross Fixed Capital Formation represents public investment of our country and we have taken FDI (inflows) as the variable while the GDP is the dependent variable. The time series data has been included here, which will be kept stationary, followed by a regression. As public investment and FDI are the independent variables, it is expected that they both have a positive relation with the dependent variable. Although, FDI may have a negative relationship to the growth. The relationship of FDI with growth rate can be used to show whether a country is in scarce of capital or not. The objective is to identify the relationship of public investment and FDI to the growth and to what extent these investments have an impact on the growth rate. By showing the estimated relationship of FDI to the GDP or growth, we are going to know whether our country is capital abundant or labor abundant.