The analytical system was constructed for the amplified fragment length polymorphism(AFLP) in Red-crowned Crane(Grus japonensis).The 5 couples of Red-crowned Crane were scanned by AFLP marker using the selective 28 primer combinations.The polymorphism and genetic cluster graph were acquired applying 10 individuals belonging to the 5 couples of Red-crowned Crane.A total of 551 polymorphism sites of the total of 1 114 bands were amplified from them.The percentage of polymorphism is 49.5%,each primer couples made 20-66 polymorphism sites.Primer E4M1 made the most,66 polymorphism sites;and primer E6M1 made the least,20 polymorphism sites.The similarity coefficient between the 10 Redcrowned Cranes was calculated,which were all in 0.71-0.88.The genetic distance and the UPGMA tree of 5 couples of Red-crowned Crane had been acquired.Cluster analysis showed that No.1 had close relationship with No.2;No.3 had also very close relationship with No.4;and the other 3 couple cranes had far genetic relationship.These showed that Red-crowned Crane has the behavioral mechanisms to identify the relationship.The study content about breeding behavioral mechanisms of Red-crowned Crane was more abundant,and puts forward some suggestions for studying deeply and founding reasonable breeding system for Semi-captive Red-crowned Crane population.