Abstract:[Objective] In this study, the distribution of Spirulina (Arthrospira) during July to September 2015 in Bohai wetland and its surrounding waters was researched. Bohai has a long coastline and relatively diverse types of wetland which provides perfect conditions for the study. Moreover, the correlation between the distribution of Spirulina (Arthrospira) and environment factors was analyzed. [Methods] The relationship between the number of Spirulina (Arthrospira) and environmental factors was analyzed through correlation and grey relational analysis. [Results] The number of Spirulina (Arthrospira) was dramatically and positively related to pH, salinity, TN, TP, COD and NH3-N (P<0.05, P<0.01) while was significantly and negatively correlated to DO (P<0.05, P<0.01). The number of Spirulina (Arthrospira) was negatively correlated with temperature as well, to which the correlation was not significant (P>0.05). The result of grey relational analysis demonstrated that the order of the correlation degree of various environmental factors on the number of Spirulina (Arthrospira) had following orders: COD>pH>TN>temperature>TP>DO>salinity>NH3-N. [Conclusion] Spirulina (Arthrospira) widely existed in Bohai coastal wetland and its surrounding waters. The environmental factors that had the most and the lest influence on the distribution of Spirulina (Arthrospira) were COD and NH3-N, respectively.