Abstract: Petroleum supply disruptions will lead to great loss of national output. As the main means to deal with supply disruptions, the drawdown of strategic petroleum reserve may make up the shortage of petroleum, which is very economically meaningful to macro-economy. This paper focuses on the estimation of economic value of strategic petroleum reserve. Firstly, energy factor is introduced into Cobb-Douglas production function as a new variable, and the empirical relationship between GNP and energy consumption is analyzed. Secondly, the significance of petroleum in the energy consumption is stated. Finally, the possible GNP losses and the decrease of economy growth rate resulted from petroleum supply disruptions are calculated, and the economic value of strategic petroleum reserve is obtained.