To investigate the effect and mechanism of andrographolide on the sensitivity of pancreatic cancer cells to cisplatin.Methods:Human pancreatic cancer cells SW1990 were divided into a control group，an andrographolide group(andrographolide treatment)，cisplatin group(cisplatin treatment)，an andrographolide+cisplatin group(andrographolide，cisplatin treatment)，andrographolide+cisplatin+transforming growth factor β1(TGF-β1) group(andrographolide，cisplatin，TGF-β1 treatment)，a TGF-β1 group(TGF-β1 treatment)，Western blot detection of TGF-β1，p-Smad2/Smad2，p-Smad3/Smad3 protein expression，MTT detection of proliferation，flow cytometry detection of apoptosis，Transwell chamber detection of invasion and migration.Results:Compared with the control group，TGF-β1，p-Smad2/Smad2，p-Smad3/Smad3 protein expression in pancreatic cancer cells in the andrographolide group decreased(P<0.05).Compared with the control group，the expression of p-Smad2/Smad2，p-Smad3/Smad3 protein in pancreatic cancer cells in the TGF-β1 group increased(P<0.05).Compared with the control group，pancreatic cancer cell proliferation activity decreased，apoptosis rate increased，the number of cell invasion and migration decreased in andrographolide group，cisplatin group，and andrographolide+cisplatin group(P<0.05).Compared with the andrographolide group and the cisplatin group，the pancreatic cancer cell proliferation activity in the andrographolide+cisplatin group decreased，and the apoptotic rate increased，the number of cell invasion and migration decreased(P<0.05).Compared with andrographolide+cisplatin group，pancreatic cancer cell proliferation activity increased，apoptosis rate decreased，the number of cell invasion and migration increased in andrographolide+cisplatin+TGF-β1 group(P<0.05).Conclusion:Andrographolide can increase the sensitivity of pancreatic cancer cells to cisplatin by inhibiting the TGF-β1/Smad2/3 signaling pathway.