Abstract: Objective To explore the effect and mechanism of recombined adenovirus carrying NLS-RARα gene on proliferation of HL-60 cells and the differentiation of HL-60 cells induced by ATRA. Methods HL-60 cells was infected with Ad-NLS-RARα and control virus Ad-KZ. The efficiency of infection was detected by FCM. The mRNA and protein levels of NLS-RARα were assessed by Real-time PCR (RT-PCR) and Western blot, respectively. MTT assay were applied to determine proliferation of HL-60 cells. Cell surface differentiation antigen CD11b of infected HL-60 cell induced by ATRA was examined by FCM. The mRNA and protein levels of C-MYC of infected HL-60 cell induced by ATRA were determined by Real-time PCR (RT-PCR) and Western blot assay. Results The efficiency of infection of Ad-NLS-RARα and Ad-KZ on HL-60 cell was 70%-80%. The mRNA and protein levels of NLS-RARα gene of HL-60 cells which infected with Ad-NLS-RARα were both obviously higher than that of the cells which infected with Ad-KZ and non-infected (P<0.05). The proliferation ability of HL-60 cell infected with Ad-NLS-RARα was significantly increased (P<0.05). The level of CD11b of HL-60 cell infected with Ad-NLS-RARα and induced by ATRA was clearly decreased than control groups (P<0.05). The mRNA and protein levels of C-MYC gene of HL-60 cells infected with Ad-NLS-RARα and induced by ATRA were both obviously higher than that of the cells which infected with Ad-KZ and non-infected (P<0.05). Conclusion The recombined adenovirus Ad-NLS-RARα can increase the proliferation ability of HL-60 cell, and inhibit the differentiation of HL-60 cell through reduce the expression level of C-MYC gene.