Abstract: Objective To understand the facultative mutualism consequence in the biodiversity conservation and its spatial and temporal characteristics. Method The ground-dwelling ant communities were investigated by pitfall traps in four types of site in Mojiang County, Yunnan Province in May and October, 2015. Result (1) Species composition and relative abundance:400 ant individuals were collected in the plot I (Fructus amomi plantation), representing 23 species; 382 ant individuals were collected in the plot II (Lac-Fructus amomi agroforestry without lac insect infestation), representing 15 species; 406 ant individuals were collected in the plot III (Lac-Fructus amomi agroforestry with lac insect infestation once), representing 18 species; 655 ant individuals were collected in the plot IV (Lac-Fructus amomi agroforestry with lac insect infestation), representing 23 species. (2) Ant diversity:there were significant differences of ground-dwelling ant species richness and relative abundance among the four sites. The richness and the relative abundance of ground-dwelling ant species increased by mutualism. The richness ranked as IV > III > II > I, and the relative abundance ranked as III > IV > II > I. (3) Community structure similarity:The ant communities of sites III and IV were dissimilar with those in sites II and I. (4) Indicator species:Tetramorium ciliatum Bolton was the indicator species of plot I, Pheidole capellini Emery and Tetramorium lanuginosum Mayr were the indicator species of plot II, Camponotus parius Emery was the indicator species of plots III and IV. Conclusion There were significant positive ecological consequences of facultative mutualism on ant species richness, relative abundance and community structure. Facultative mutualism had spatial and temporal effects on biodiversity conservation.