OBJECTIVE: To analyze the action of miRNA-326 on its target gene BCL-XL and the molecular mechanism of platelet apoptosis regulated by miRNAs. METHODS: Dual-luciferase vectors containing respectively the wild-type and mutant 3'-untranslated region (3'UTR) fragments of the BCL-XL gene were constructed with firefly and renilla luciferases and transfected into 293T cells. Relative fluorescence intensities of the transfected cells were measured. RESULTS: Dual-luciferase reporter gene vectors for PsiCHECK- BCL-XL -3'UTR-WT (wild-type) and PsiCHECK- BCL-XL -3' UTR-MT (variant) were respectively constructed. Relative fluorescence intensities of the 293T cells co-transfected by miRNA-326 and PsiCHECK- BCL-XL -3'UTR-WT plasmid were significantly lower compared with the control group (co-transfected by a miRNA-326 negative sequence and PsiCHECK- BCL-XL -3' UTR-WT plasmid) ( P = 0.034). The relative fluorescence intensity was also significantly reduced in cells co-transfected by miRNA-326 and PsiCHECK- BCL-XL -3' UTR-WT plasmid compared with the mutant control group co-transfected by miRNA-326 and PsiCHECK- BCL-XL -3'UTR-MT plasmid (P = 0.022). CONCLUSION miRNA-326 may participate in the regulation of platelet apoptosis by acting on the 3'-UTR of the BCL-XL gene.