Bioluminescence(BL)is an amazing natural phenomenon whose visible light is pro-duced by living organisms.Due to its high sensitivity,high selectivity and high sig-nal-to-noise ratio,BL has been applied broadly in biotechnology and biomedical fields.However,for centuries,we can only receive some sporadic and static infor-mation from experimental observations,the mechanism of most BL is unknown.In the past 14 years,we have been performing theoretical study on all kinds of biolu-minescent systems,and have uncovered the mechanism and details of several BLs.Here as an example,we qualitatively introduce our theoretical study of firefly BL in this account.