Abstract: In this paper，taking pure forests of previously created Eucalyptus camaldulensis and Leucaena leucocephala in the Yuanmou aridhot valley as a reference, the comprehensive ecological and economic benefit of previously built Acacia suma mixed forest with Eucalyptus camaldulensis was investigated. The results showed that in the first rotation the biomass output of the Acacia suma mixed forests was up to 1920t/hm2, according to the calorific value of about 118 t/hm2 of standard coal equivalent, and significantly higher than that of pure forest Eucalyptus camaldulensis (708t/hm2),Leucaena leucocephala (547t/hm2) and Acacia suma(297t/hm2); Its economic benefits (net income,￥12 300 per hm2) were the Eucalyptus camaldulensis pure forest of 1.7 times, the Leucaena leucocephala pure forest of 3 times and the Acacia suma pure forest of 9.2 times, respectively. The ratios of input to output (10∶59) slightly lower than the Eucalyptus camaldulensis pure forest, but significantly higher than the two pure forests of the Leucaena leucocephala forest and the Acacia suma forest. In addition, the mixed forest model had a high degree of stability and realization of natural regeneration. The suggests that in the dryhot valley areas popularization of Acacia suma mixed forests not only provide firewood, and nontimber products, and also has important practical significance for vegetation restoration, reconstruction.