Objective: To investigate the relationship between the activation markers of platelets and the lung cancer. Meth- ods: Based on international stages of lung cancer in 1997, lung cancer patients of 120 cases diagnosed by pathology as well as with operation indication were selected as the experimental group. During the process of experiment, 60 cases concluded as healthy in the physical examination were chosen as control group. The activation markers of platelets were detected by FCM method. The experimental result would be processed by SPSS 11.5. Results: The level of activation markers of platelets in peripheral blood of lung cancer patients was significantly higher than those healthy people (P < 0.01). The level of activation markers of platelets in peripheral blood of lung cancer patients on the seventh postoperative day was significantly lower than that before operation and on the first postoperative day (P < 0.01). The level of activation markers of platelets in peripheral blood of lung cancer patients was closely related to the size of the primary tumor, lymph node status and stages, but not to the grade of cell differentiation, type of tumor, age, sex of the patients (P > 0.05). Conclusion: Elevation of the level of activation markers of platelets in peripheral blood exists in lung cancer patients and the levels of activation marker of platelets plays an important role in tumor growth and lymphatic metastasis. The levels of activation markers of platelets maybe a predictor for prognosis. Objectives: To investigate the relationship between the activation markers of platelets and the lung cancer. Meth ods: Based on international stages of lung cancer in 1997, lung cancer patients of 120 cases diagnosed by pathology as well as with operation indication were selected as the The experimental results would be processed by SPSS 11.5. Results: The level of activation markers of platelets in peripheral blood of lung cancer patients was significantly higher than those of healthy people (P <0.01). The level of activation markers of platelets in peripheral blood of lung cancer patients on the seventh postoperative day was significantly lower than that before before operation and on the first postoperative day (P <0.01). The level of activation markers of platelets in peripheral blood of lung cancer patients was closely related to the size of the primary tumor, lymph node status and stages, but not to the grade of cell differentiation, type of tumor, age, sex of the patients (P> 0.05). Conclusion: Elevation of the level of activation markers of platelets in peripheral blood exists in lung cancer patients and the levels of activation marker of platelets plays an important role in tumor growth and lymphatic metastasis. The levels of activation markers of platelets maybe a predictor for prognosis.