The objective of this paper is to estimate the potential magnitude in natural gas price adjustment if tariff and excise are reduced and the duration for depreciation is doubled. Furthermore, we evaluate the impact of price decrease in natural gas on the demand for natural gas and the economy. For this, a dynamic general equilibrium model of Taiwan (DGEMT) or Liang-Jorgenson model (2001) is employed. The major findings are: If tariff and excise are reduced and the duration for depreciation is doubled, the price of natural gas can decrease by 5.53% to 12.56%. As a result, the general price level (GDP deflator) will decrease by 0.03% to 0.08%, while the economic growth will increase by 0.01 % to 0.03%. And the demand for natural gas will rise by 2.5% to 5.8%. Consequently, government should carry out the policy of rationalizing the natural gas price as quickly as possible.