Objective To establish in vitro model for perineural invasion (PNI) of pancreatic cancer,and observe the process of PNI.Methods Mouse dorsal root ganglia (DRG) and pancreatic cancer Capan-2 cell line were co-cultured in Matrigel matrix.Two models were constructed:model 1 for observing areas of cell colonies and model 2 for observing distance of cell migration.Neurite outgrowth and cell colony growth were observed by invert microscope,images were analyzed by using Image pro plus software.Results Neurite outgrowth was not affected by co-culture.DRG neurite appeared radial growth under either co-culture or single culture.It was observed that Capan-2 cell could migrate to DRG,and grows around the nerve fiber as spindleshaped,then continue to migrate to DRG.At the 5th day,in the co-culture group of model 1,the colony area was (309.28 ±19.11) μm2,which was significantly bigger than that in single culture model [(208.57±7.94) μm2,P ＜0.01].At the 5 th day,in the co-culture group of model 2,Capan-2 migrated (284.1 ±12.9) μm to DRG,while in the side of blank Matrigel,cell migrated less than 150 μm,the difference was statistically significant (P ＜0.01 ).Conclusions The in vitro models for perineural invasion in pancreatic cancer were constructed successfully,which lay a good foundation for future studies.