Abstract: Loufan County is an important ecological barrier and water source in Taiyuan. Evaluating its ecosystem service value（ESV） is of great significance to maintain regional ecological security. The research applies the equivalent factor method of unit area value to evaluate the ESV of Loufan County in 2010, 2015 and 2020. The research shows that the maximum average value of ESV in Miyu Township is 72 110.149 ×104yuan, the maximum annual average ESV density in Loufan town is 47 411.27 yuan/hm2, and the annual average ESV and annual average ESV density in Jingyou Town are the minimum. During the 10 years from 2010 to 2020, the ESV in Loufan County generally showed a continuous downward trend, and the substantial increase in the area of desert and bare land is the main reason for the decline of ESV in Loufan County.