In this study, taking the interface of moso bamboo (Phyllostachys edulis)Chinese fir (Cunninghamia lanceolata) forest as the research object, we compared and analyzed contents and correlations of soil organic carbon (SOC), total nitrogen (N), total phosphorus(P), alkalihydrolyzed nitrogen(HN) and available phosphorus(AP) at different expansive stages to reveal the effects of moso bamboo expansions on soil nutrients and stoichiometric characteristics, and to provide basis for rational regulation and ecological management of moso bamboo forest. The study shows: (1) for moso bamboo to Chinese fir, with the increase of moso bamboo proportion, the content of SOC increased first and then decreased, and the coefficient of variation of SOC increased gradually with the deepening of soil layer; the content of N increased first and then decreased, and the final stage of expansion is higher than the initial stage of expansion; The contents of P, HN and AP showed wavelike change trend with the expansion of moso bamboo. The contents of P, HN and AP in different expansion stages reached significant levels. The contents of P and AP in final expansion stage were lower than that in initial expansion stage, and the content of HN was higher than that in initial expansion stage. (2) During the expansion of moso bamboo to Chinese fir, C∶N showed an upward trend with the expansion of moso bamboo, and the difference between different expansion stages reached a significant level; N∶P showed an upward trend with the expansion of moso bamboo. The difference of N∶P in 0-20 cm soil layers reached a significant level, while that in 20-30 cm soil did not reach a significant level. HN∶AP increased first and then decreased with the expansion of moso bamboo, and the difference between different expansion stages reached a significant level, and the final expansion stage was smaller than the initial expansion stage. (3) SOC, N, P and C∶N, N∶P, HN∶AP are significantly correlated, and the correlation coefficient reaches a significant level. Among them, SOC and N are negatively correlated with HN∶AP, P is negatively correlated with N∶P and HN∶AP. This reflects that with the expansion of bamboo, soil N and P elements were more scarce. It is suggested that N and P elements be supplemented in time to promote the stable and healthy development of community.