Objective To adopt accurate and prompt nursing measures to prevent incidence of pressure through evaluation of risk factors of pressure ulcer during perioperation of thoracotomy, in order to increase nursing quality and life quality of patients. Methods The incidence of pressure ulcer in 100 patients after thoracotomy and its related risk factors were investigated by application of pressure ulcer risk factors evaluation scale, and the influence of related factors on incidence of pressure ulcer was com -pared. Results Single factor analysis showed that preoperative smoking, albumin content and prolonged postoperative turning over time had significant influence on incidence of pressure ulcer. Conclusions Patients after thoracotomy are high risk population of pressure ulcer. The pivotal period for ulcer prevention is from the operation day to 3 days after operation.