The rhizosphere effect and variation characteristics of quantitative distribution of microorganisms related to nitrogen transformation from four strand plants in zhoushan coastal areas were studied using the methods of spread-plate and MPN. The results showed that the rhizosphere effect of microorganisms related to nitrogen transformation from four strand plants was significant. There are slight difference in the quantitative distribution of azotobacteria, nitrifying bacteria, silicate bacteria, and ammonifilation bacteria from the rhizpsphere of four strand plants. Not only the total number of four Microbe Group related to nitrogen transformation but also the rhizosphere effect, Carex kobomugi has obvious advantage in comparison with others. The paper also showed that the effects of season on rhizosphere microorganisms associated with nitrogen transformation were different.