||This paper explains the method using a set of night light imaginary to estimate GPP of Thailand. This method is quite new but widely acceptable in the area of economics because luminosity of night lights is normally based on the amount of economic activities in each area. The results showed a high and significant correlation betweein the night lights and the GPP growth. Even if the estimation was controlled by some specific factors, such as population density, timing size of agricultural or manufacturing sector, the relationship is still robust. After this relationship is confirmed in the provincial level of Thailand, this research applied the results to show the relationship between economic values and spatial inequality, which indicates new understanding about spatial development patterns.