Abstract: Objective · To investigate the natural depression model of Macaca fascicularis inducedsubmissive-aggressive behaviors. Methods · In a simulated wild environment, two Macaca fascicularis groups (G1 and G2) were respectively established. The two groups consisted of 19 and 14 Macaca fascicularis respectively. The effective frequency of each groups submissive-aggressive behaviors was observed and recorded, the matrix of submissive-aggressive behaviors was analyzed, each individual of the group was calculated separatelyDavid’s score(DS), according to the level of individual DS, each group was divided into attack group and yield group; the behavior changes of each individual in 7 periods were recordedthe focus observation and the correlation analysis of 11 different behaviors was carried out. Results · After the formation of these groups, there was fierce conflict between the cynomolgus monkeys. 1 122 and 1 409 submissive-aggressive behaviors were recorded in the two groups respectively. In the submissive-aggressive behavior matrix, the differences between high and low DS in anxiety behavior (t1 -4.053, P10.005; t2 -3.041, P20.012), conflict behavior (t18.478, P10.018; t27.651, P20.002), depression behavior (t1 -3.691, P10.006; t2 -2.431, P20.045) and exercise behavior (t19.639, P10.007; t23.568; P20.002) were statistically significant. Conclusion · The natural depression model of caged Macaca fascicularis is a social defeat model inducedyield-attack behavior.

Key words: depression, Macaca fascicularis, submissive-aggressive behaviors, Davids score, social defeat