Objective　To measure the platelet to lymphocyte ratio (PLR) of young acute cerebral infarction (young acute cerebral infarction,YACI) patients,and to analyze its possible correlation with hemorrhagic transformation (HT) in YACI patients.Methods　According to the occurrence of HT,152 YACI patients admitted were divided into HT group (36 cases) and non hemorrhagic transformation group (116 cases).According to the bleeding volume,HT group was divided into large bleeding group (8 cases),medium bleeding group (11 cases) and small bleeding group (17 cases).The degree of neurological deficit was evaluated according to NIHSS score.The relationship between PLR and HT and NIHSS score in YACI patients was analyzed.Results　The PLR value in the observation group was significantly higher than that in the control group,there were significant differences in the NIHSS score of mild group,moderate group and severe group,the PLR value in HT group was higher than that in non HT group,there were significant differences among SH group,MH group and LH group (all P<0.05).The PLR value in the observation group was positively correlated with NIHSS score (r=0.638,P=0.036),and the PLR value in HT group was positively correlated with bleeding volume (r=0.714,P=0.029).Conclusion　The increase of PLR in YACI patients was positively correlated with post YACI bleeding volume and NIHSS score,which could predict the possibility of HT in YACI patients to a certain extent.