Abstract:Objective Swrodtail,Xiphophorus hellerii was an aquatic experimental animal authorized by the original thoroughbred committee and published by the ministry of agriculture. It shows a good prospect in genetic research experiment,water environment pollution monitoring and bacterial disease research. In order to monitoring the germplasm resources of swordtail,distinguish the inbred lines and wild swordtail and identify the purity of inbred lines,microsatellite DNA fingerprint was used in this study. Methods 50 pairs of microsatellite primers were synthesized according to related reports. Among which,train-special primers used to identify the inbred lines of swordtail and core primers used to draw the DNA fingerprinting schema graph were screened. Then we constructed the DNA fingerprint using scatter diagram method with EXCEL 2003 software. Digital fingerprint barcode data had input software of PRIFRI V1. 0,which had formed a standardization fingerprint identification database of swordtail. Results We together received five pairs of strain-special microsatellite primers and 46 core primers. The DNA fingerprinting of RR-B,RW-H and wild swordtail were constructed.And a fingerprint identification database of swordtail was formed. Conclusion Using these microsatellite markers and DNA fingerprinting,we can identify varieties,purity and genetic monitoring of RR-B,RW-H and wild swordtail.