Objective To investigate the effects of psoralen on HepG2 cells by transcriptome sequencing technology(RNA-seq).Methods The effects of various concentrations of psoralen(0、62.5、125、250、500 μM)on the viability of HepG2 cells after 12 h and 24 h treatment were detected by CCK-8 assay.The cell cycle of HepG2 cells exposed to 250 μM psoralen for 24 h was detected by flow cytometry.RNA-seq followed by GO enrichment analysis and KEGG pathway enrichment analysis identified differentially expressed genes between control and psoralen groups.qPCR was conducted to verify the gene expression levels of target genes.Results Compared with the control group,the cell viability rate of HepG2 cells after treated with psoralen was significantly decreased(P<0.01),and the cell cycle in the G0/G1 phase was increased(P<0.05).There are 286 differentially expressed genes in psoralen groups,of which 130 were up-regulated and 156 were down-regulated.The GO enrichment analysis and KEGG pathway enrichment analysis were mainly involved in the biological processes and signal pathways related to the cell cycle.The qPCR results showed that p53 and GADD45B gene expression was up-regulated(P<0.05,P<0.01),CDK2,RRM2 and CCND1 gene expression was down-regulated by treatment of Psoralen in HepG2 cell(P<0.05,P<0.01).Conclusion Psoralen has toxic effects on HepG2 cells and inhibition of cell cycle progression.The mechanism may be related to the regulation of the expression of cell cycle genes(p53,CDK2,GADD45B,CCND1,RRM2).