Abstract: Objective To explore the lung toxicity of the volatile mixtures of polyurethane paint for decorative use.Method The broncho-alveolar lavage fluid elements among rats were determined after 1,3 and 7 day-exposure to the volatile mix tures of polyurethane paint(2 hours per day).Results The results showed that acid phosphatase(ACP)in bronchoalveolar lavage fluid in exposed groups was increased significantly compared with control group after 7 day-ex psoure.Conclusion Alveolar macrophage (AM),lactate dehydrog enase(LDH),alkaline phosphatase (AKP),albumin(ALB)had no sig nificant differences between exposed groups and control groups.It indicated that the volatile mixtures of polyurethane paint was harmful to AM.