Using field observation data, the characteristics of surface energy in summer in grassland of Qilian mountain and Zhangye Gobi of Hexi corridor were analyzed, as well as the relations between environment factors and characteristics of surface energy were discussed. The results indicated that RN and LE flux in grassland is higher than that in Gobi, and Hs and soil heat flux in Gobi is higher than that in grassland on a typical clear day in summer. In grassland LE is three times as large as Hs and soil heat flux. In Gobi Hs and soil heat flux is twice as large as LE. The surface energy is not balance in grassland and Gobi. In grassland the sum of LE, Hs and soil heat flux is smaller than RN. In Gobi the sum of LE, Hs and soil heat flux is bigger than RN. The difference between RN and sum of LE, Hs and soil heat flux on a cloudy day is bigger than that on a clear day as well as it in Gobi is bigger than that in grassland. Main environment factor that influences the difference of RN in grassland and Gobi is sun's  radiation. Main environment factors that influence the difference of LE, Hs and soil heat flux in grassland and Gobi are surface vegetation and water.