This study aims at evaluating the effects of Bifidobacterium Lactis BB-12 and Lactobacillus plantarum P-8 on the behaviors and gut microbiota in a depression model induced by chronic unpredictable mild stress （CUMS）. A depressed rat model was established by CUMS combined with separation. After 8 weeks， depressed model rats were treated with Bifidobacterium lactis BB-12 and Lactobacillus plantarum P-8 for six weeks by gavage. Additionally， healthy control group （HC） and model control group （CUMS） were given the same volume of sterile water. Behavioral tests were performed before and after gavage. After the end of the treatment， fecal samples were collected for 16S rRNA V4-V5 regions high-throughput sequencing. Results showed that two probiotics improved CUMS-induced depressed behaviors （including attenuated the decreased sucrose preference in the sucrose preference test and developed the activity and exploration of CUMS rat in the open field test， as well as in the light / dark test， pronounced decreased the time of CUMS rat spent in the dark zone） compared with CUMS group. Nonmetric Multidimensional Scaling （NMDS） revealed that probiotic supplement groups significantly modified the overall structure of the fecal bacterial community when compared to control groups （HC and CUMS）. Furthermore， two prebiotics also resulted in altering specific taxonomic compared with the control groups， including Bifidobacterium Lactis BB-12 decreased the levels of OTU556， OTU194 and OTU99 while Lactobacillus plantarum P-8 reversed the changes of OTU556， OTU194， OTU99 and OTU198. PICRUSt analysis revealed that a number of functions about intestinal microflora were disturbed by CUMS， and the two probiotics can only relieve dysfunction to a certain degree. Taken together， these results indicate an anti-depressant effect of Bifidobacterium Lactis BB-12 and Lactobacillus plantarum P-8 in rats subjected to CUMS and that this effect could be due to regulating the structure， composition and function of gut microflora.