Based on the Production Function Model, the paper analyzes the interrelation of transportation infrastructure investment and economic growth in different provinces from 1994 to 2009. And in the conditions of constant returns to scale and increasing returns to scale, the paper also calculates the output coefficients of provincial transportation infrastructure investment respectively. The result is that the promotion effect of transportation infrastructure investment to economic growth is greater in developed region, and transportation infrastructure, on which investing should focus on the long term development of economy, is the necessary condition to the promotion of economic growth rather than the sufficient condition.