Abstract: Two steps have been designed to assess the invasion risk of butterfly releasing. Firstly,the authors discussed only on four key factors,i.e.host plants,high temperature in summer and low temperature in winter,and determining if a newly introduced butterfly species could keep alive in a new territory or not.And this is decided by the value of Rc,which is called as risk coefficient.If Rc is equal to 0,it means the introduction of a butterfly species is quite safe,and the adults could be permitted to be released outdoors;if Rc=1,it meas the invasion may take place,so intensive assessment needed to be done.In the second step,a assessment was made on many factors such as host-plant,temperatures in summer and winter,time of generation,speed of expansion spread,etc.,and give each factor a score of risk(X_i).The scores were added together and obtained the total score Sd.The invasion risk of a alien butterfly species could be judged by the value of R,and R = Rc.Sd.If R≥20,live butterflies should not be introduced to the new territory.When 20R≥10,live butterflies should only be permitted to release in an isolated area.If R5,the adults of introduced species could be released into a non natural-protection territory.In the administration of live butterfly releasing,some important measures must be taken to guarantee the safety.