Abstract： Objective To explore the influence of LPS treatment on related molecules in Smads and ERK1/2 signal pathway in pancreatic stellate cell line LTC-14.Methods LTC-14 cells were cultured in vitro, and were treated with LPS at different dose in different time points.Protein expressions of related molecules in Smads pathway and ERK1/2 pathway and α-SMA in LTC-14 Cells were examined by Western blot.Results On Treated LTC-14 cells by 0, 1, 5, 10, 20 and 50 mg/L LPS,protein expressions of Smad3 were 0.15±0.02, 0.37±0.02, 0.44±0.01, 0.46±0.02, 0.372±0.01 and 0.24±0.03;expressions of Smad7 were 0.79±0.05, 0.84±0.02, 0.55±0.03, 0.45±0.03, 0.34±0.02 and 0.92±0.07;p-ERK1/2 levels were 0.48±0.05, 0.74±0.03, 0.72±0.04, 0.89±0.02, 0.81±0.02 and 0.72±0.03;p-cPLA2 levels were 0.15±0.03, 0.30±0.01, 0.31±0.01, 0.30±0.02, 0.28±0.03 and 0.32±0.02;α-SMA levels were 0.56±0.06, 0.62±0.06, 0.54±0.04, 1.03±0.11, 1.39±0.08 and 1.28±0.10.The changes of protein expressions before and after LPS treatment were obvious (all P<0.01).The protein expressions of ERK1/2 were 0.56±0.03, 0.57±0.02, 0.53±0.02, 0.58±0.02, 0.59±0.05 and 0.55±0.04, which did not change obviously along with increased LPS dosages.LTC-14 cells treated with 10 mg/L LPS for 0, 1, 3, 6 and 9 h,the expressions of Smad3 were 0.69±0.05, 0.68±0.07, 1.02±0.14, 1.82±0.0 and 2.04±0.11,those of Smad7 were 2.77±0.10, 1.37±0.08, 1.45±0.14, 0.78±0.09 and 0.63±0.06,those of p-ERK1/2 were 0.16±0.03, 0.32±0.05, 0.79±0.03, 1.50±0.07 and 1.77±0.04,those of p-cPLA2 were 0.15±0.04, 0.32±0.06, 0.63±0.04, 0.95±0.04 and 1.49±0.10,those of α-SMA were 0.84±0.03, 1.26±0.21, 1.81±0.19, 4.28±0.26 and 4.37±0.15, all of which changed obviously as the treatment time increased (P<0.05 or 0.01).The expressions of ERK1/2 were 0.75±0.03, 0.72±0.02, 0.80±0.04, 0.74±0.03 and 0.85±0.09, which did not change obviously as the treatment time increased.Conclusions LPS could upregulate the expression of α-SMA in a time-and dose-dependent way, and activate intracellular Smads and ERK1/2 inflammatory pathways, which may be the potential molecular mechanism of the development of chronic pancreatitis.