Objective To explore the effective laboratory markers for predicting adverse cardiovascular events in the patients with coronary slow flow phenomenon (CSFP). Methods A prospective study was carried out on 54 patients who underwent coronary angiography (CAG) and diagnosed with simple CSFP in our department from January 2013 to December 2014. According to the incidence of adverse cardiovascular events during the follow-up, they were divided into adverse events group (n=10) and adverse events-free group (n=44).The laboratory indicators and echocardiographic parameters were compared and analyzed between the 2 groups. Statistical data from univariate analysis and laboratory indicators predicting CSFP prognosis were included in the Cox regression model. The most significant independent risk factors were included in the receiver operating characteristic (ROC) curve analysis. Kaplan-Meiers survival analysis was used to compare the incidence of adverse cardiovascular events among the patients with different risk factors. Results The serum contents of triglycerides (TG), apolipoproteins B (ApoB), creatine kinase MB isoenzyme (CK-MB), and plasma prothrombin activity (PTA)were significantly higher in the adverse events group than the adverse events-free group(HR=1.193, 95%CI 1.036-1.374, P<0.05). Cox regression analysis showed that increased PTA was an independent risk factor for poor prognosis(P<0.05). Kaplan-Meiers survival analysis also indicated that those with higher PTA had higher incidence of adverse events than those with low PTA (P<0.05). The plasma PTA showed good correlation between the ROC curve and adverse cardiovascular events during the follow-up period after discharge (area under the curve=0.717, P=0.033). Conclusion PTA can be used as an indicator in the prediction of long term adverse events in CSFP patients.