To explore the role of apoptosis, apoptosis regulating genes in the pathogenesis and development of smoke inhalation injury. With smoke inhalation injury rat model, the changes int the expression of Bcl 2, Bax, Fas, FasL genes mRNA and protein contents and their relationship with apoptosis of lung tissue cells at different time points after the injury were observed with TUNEL, immunohistochemistry and RT PCR techniques. The results showed that: ①apoptosis indet of lung colls after smoke inhalation injury increased, ②expressions of Bcl 2, Bax, Fas, FasL genes were obviously up regulated in injury group, peaking at the 12th hour, whereas the peak of protein expression was at the 24th hour. Furthermore, a significant correlation was found between the expression of Fas, Fasl, Bax gene and apoptosis indices in lung cells. The results suggested that apoptosis participated in the early pathological process of smoke inhalation injury, and apoptosis regulating genes foot part in the regulation of apoptosis in smoke inhalation injury.