Aim To evaluate the effect of LDL and ox LDL on the activity and mRNA expression of hepatic lipase (HL) in HepG2 cells. Methods Gradient concentrations (1.7～1 758 mg/L) of LDL or ox LDL was added into the medium and coincubated with HepG2 cell. The cytostasis rate of HepG2 cell was estimated by MTT and the activity and mRNA expression of HL in these cells were measured with cytochemistry and RT PCR respectively. Results In the 27.47 mg/L and 54.95 mg/L LDL groups, the mRNA expression of HL was up regulating 2.8 times and 2.3 times respectively to the cell control. In the 109.8 mg/L LDL, the mRNA expression of HL decreased 20% to the cell control. The HL activity in HepG2 cells incubated with LDL was negative related with the LDL concentration (r=-0.95614, p<0.05). The cytostasis rate in LDL increased by dose dependent model (r=0.91199, p<0.05). In the ox LDL group, the mRNA expression of HL was inhibited at all concentrations. In 27.47 mg/L and 54.95 mg/L ox LDL, the activity of HL was 3～4 times as much as that of LDL groups. Moreover, at the same concentration of 54.95 mg/L, the cytostasis rate in the ox LDL group was one time higher than in the LDL group. Conclusions At the appropriate range of concentration, LDL can induce the up regulation of mRNA expression of HL. High concentration of LDL and all concentration of ox LDL can inhibit not only mRNA expression but the activity of HL in HepG2 cells.