AIM:　To　develop　an　affinity　peptide　that　binds　to　gastric　cancer　used　for　the　detection　of　early　gastric　cancer.　METHODS:　A　peptide　screen　was　performed　by　biopanning　the　PhD-12　phage　display　library,　clearing　non-specific　binders　against　tumor-adjacent　normal　appearing　gastric　mucosa　and　obtaining　selective　binding　against　freshly　harvested　gastric　cancer　tissues.　Tumor-targeted　binding　of　selected　peptides　was　confirmed　by　bound　phage　counts,　enzyme-linked　immunosorbent　assay,　competitive　inhibition,　fluorescence　microscopy　and　semi-quantitative　analysis　on　immunohistochemistry　using　different　types　of　cancer　tissues.　RESULTS:　Approximately　92.8%　of　the　non-specific　phage　clones　were　subtracted　from　the　original　phage　library　after　two　rounds　of　biopanning　against　normal-appearing　gastric　mucosa.　After　the　third　round　of　positive　screening,　the　peptide　sequence　AADNAKTKSFPV　(MD)　appeared　in　25%　(12/48)　of　the　analyzed　phages.　For　the　control　peptide,　these　values　were　6.8　+/-　2.3,　5.1　+/-　1.7,　3.5　+/-　2.1,　4.6　+/-　1.9　and　1.1　+/-　0.5,　respectively.　The　values　for　MD　peptide　were　statistically　significant　(P　＜　0.01)　for　gastric　cancer　as　compared　with　other　histological　classifications　and　control　peptide.　CONCLUSION:　A　novel　peptide　is　discovered　to　have　a　specific　binding　activity　to　gastric　cancer,　and　can　be　used　to　distinguish　neoplastic　from　normal　gastric　mucosa,　demonstrating　the　potential　for　early　cancer　detection　on　endoscopy.　(C)　2012　Baishideng.　All　rights　reserved.