Objective: To observe the effect of insulin-like growth factor-1 (IGF-1) on bone morphogenetic protein (BMP)-2 expression in hepatocellular carcinoma SMMC7721 cells. Methods: Cells were divided into blank control, IGF-1, IGF-1 + SB203580, and SB203580 groups. SB203580 was used to block the p38 MAPK signaling pathway. Changes in the expression of BMP-2, p38 MAPK, and phosphorylated p38, MERK, ERK and JNK were determined using reverse transcription polymerase chain reactions (RT-PCR) and Western blot analysis. Results: Protein expression of phosphorylated BMP-2, MERK, ERK, and JNK was significantly up-regulated by IGF-1 compared with the control group ($1.138{pm}0.065$ vs. $0.606{pm}0.013$, $0.292{pm}0.005$ vs. $0.150{pm}0.081$, $0.378{pm}0.006$ vs. $0.606{pm}0.013$, and $0.299{pm}0.015$ vs. $0.196{pm}0.017$, respectively; P<0.05). Levels of BMP-2 and phosphorylated MERK and JNK were significantly reduced after blocking of the p38MAPK signaling pathway ($0.494{pm}0.052$ vs. $0.165{pm}0.017$, $0.073{pm}0.07$ vs. $0.150{pm}0.081$, and $0.018{pm}0.008$ vs. $0.196{pm}0.017$, respectively; P<0.05), but such a significant difference was not observed for phosphorylated ERK protein expression ($0.173{pm}0.07$ vs. $0.150{pm}0.081$, P>0.05). Conclusion: IGF-1 can up-regulate BMP-2 expression, and p38 MAPK signaling pathway blockage can noticeably reduce the up-regulated expression. We can conclude that the up-regulatory effect of IGF-1 on BMP-2 expression is realized through the p38 MAPK signaling pathway.