Objective：To select microRNA，which plays an important role in the apoptosis of vascular smooth muscle cells（VSMC） af－ter subarachnoid hemorrhage（SAH） by microRNA microarray. Methods：Firstly，the model of VSMC apoptosis after SAH was estab－lished，then，microRNA microarray was used to screen differentially expressed microRNA. Finally，the screened out microRNA145 was validated by qRT-PCR and biological information database was used to predict the possible target genes. Results：Model of VSMC apoptosis after SAH was established successfully. MTT assay showed that A value of 200 μmol/L OxyHb group was 0.197±0.131 after 24 h and apoptosis rate was 30.233±7.23，with significant differences compared with those of other groups（P<0.05）. There were 22 differently expressed microRNAs，16 microRNAs of which were up-regulated，6 microRNAs were down-regulated obviously and microRNA145 was the greatest change one among them. MicroRNA145 expressed highly in VSMC after SAH，which was validated by qRT-PCR. It was suggested that Bcl-2/E1B 19 kDa-interacting protein 3（BNIP3） may be the target gene for it. Conclusions：mi－croRNA145 may be the molecular target regulating VSMC apoptosis after SAH. MicroRNA145 causes apoptosis of VSMC after SAH，induce and increase cerebral vasospasm possibly through BNIP3 related signaling pathways.