Abstract： Objective：To observe the relationship between the Grace score and ratio of neutrophils to lymphocyte (NLR) in the patients with acute coronary syndrome (ACS). Methods：171 patients with ACS and 75 healthy controls were enrolled in this study. According to Grace scores，the patients with ACS were divided into three groups，the highrisk group with Grace score greater than 140，the middlerisk group with Grace score between 109 to 140，and the lowrisk group with Grace score less than or equal to 108. The levels of creatine kinase isoenzymeMB(CKMB)， troponin I (cTnI), creatinine(Cr) , WBC, N(%) and L(%) in patients with ACS and healthy controls were determined, and the ratio of neutrophils to lymphocytes were calculated. Their relationship were analyzed. Results：Compared to healthy controls，the WBC, N(%) and NLR were significantly increased (all P＜0.01)，while the L(%) was significantly decreased (P＜0.01) in the patients with ACS. The levels of NLR in highrisk group were significantly higher than those in the midrisk group (P＜0.05) and lowrisk group (P＜0.01)，and the midrisk group were higher than lowrisk group (P＜0.05). Correlation analysis showed that the levels of NLR were significantly positively related with Grace score (r=0.26，P＜0.05). Conclusion：The levels of NLR in patients with ACS were related to Grace scores.