P311 is an 8 kDa protein that has been shown to be of importance in the process of myofibroblast transformation, glioblastoma invasion and nerve regeneration. However, the interaction protein of P311 has yet to be found. The purpose of this study was to find the interactive protein of P311.The yeast two-hybrid system was used for screening the potential interaction proteins of P311. Joint expression of the potential interactive protein and P311 was immunohistochemically stained. The interaction between P311 and the selected protein was further confirmed by fluorescence resonance energy transfer (FRET) in pulmonary adenocarcinoma tissue sections, and by coimmunoprecipitation in HEK293.Integrin β4 binding protein (ITGB4BP) was confirmed as the interaction protein of P311. Co-expression and interaction of ITGB4BP and P311 were demonstrated in pulmonary adenocarcinoma by both immunohistochemistry and FRET. Moreover the interaction between P311 and ITGB4BP was demonstrated by coimmunoprecipitation in HEK293.The interactions between P311 and ITGB4BP may be very important in the process of tumor cell differentiation and metastasis. ITGB4BP may provide a potential new target for the therapy of tumors.