Abstract: The interactions of water and nitrogen (N) on soil bacterial community were analyzed in a simulated indoor incubation experiment. The main factor included soil moisture (70% and 100% field capacity), and the split factor was N addition form (no N application, pure inorganic N, pure organic N, 2/3 inorganic N + 1/3 organic N, and 1/3 inorganic N + 2/3 organic N). The results showed that the interaction of water and nitrogen had significant influences on the content of soil inorganic N and the Shannon and Simpson indices of soil bacterial community. Moreover, the content of soil inorganic N in the high soil water treatment was significantly decreased (P < 0.05), while the Shannon, Ace and Chao1 indices of soil bacterial communities were significantly increased (P < 0.01). The relative abundances of Aeromonas and Flavobacterium were increased with the increase of soil moisture content. Compared to the inorganic N treatment, the organic N treatments significantly accelerated the content of soil organic N after 30 days of incubation. With the addition of organic N, the relative abundances of Cellvibrio and Devosia also increased. In conclusion, although organic N fertilization in the protected vegetable field could not be conducive to the increase of soil available N, the dominant bacterial populations changed under the appropriate water condition. Soil carbon-N cycle is supposed to tend toward stability with the increased richness of the specific carbon assimilating bacteria. The results may provide a new insight for understanding the environment-driven mechanisms for soil carbon and N cycling functional microbes, in response to the different water and N managements in the protected vegetable filed.