With the intensification of global warming,Cylindrospermopsis raciborskii appeared to transfer and expand from tropical and subtropical freshwaters into temperate zones. The major environmental issue caused by the excessive reproduction ofC. raciborskii is the massive production of its toxic metabolite, cylindrospermopsin (CYN). This kind of cytotoxin is highly soluble in water and stable for a long time, representing serious health risks as well as environmental threats all over the world. In recent years, international research about CYN is increasingly prevalent and broad across many countries. However, studies on this field are very poor in China so far. This paper provided a comprehensive review of the structure and characteristics of CYN as well as its potential effects on aquatic organisms, soil plants, and human beings according to the current state of knowledge. This paper also summarized the possible mechanism involved in the toxicity of CYN and put forward their further investigation and development.