Objective: To observe the precess of evoking high risk complications when using ATRA to induce differentiation therapy acute promyelocytic leukemia(APL),to provide criteria which could be useful for earlier diagnosis and therapy. Methods: Ten patients with primary APL and clinical data was assessed with unification centification. Results:In the induction period the main complications which would be dangerous for the life ,were hyperleucocytosis symptom and RAS,and their incidence were 90% and 10% separately. Conclusion: In the period of therapy using ATRA,we should pay close attention to the clinical situation and leucocyte number,and medicating on time,in order to save the patients’ life.