In this paper， SSR sites were screened from the sheep expression sequence tag in NCBI system (EST) database by SSR Finder software and MISA technology， and sheep EST-SSR fluorescent primers were designed using Primer 3.0 to differentiate the products of Ningxia Tan lamb， Xinjiang fine-wool sheep meat and Tibetan lamb. Experiments were PCR amplified using liver DNA from three sheep as templates for designed EST-SSR primers and detected SSR typing using capillary electrophoresis. The results showed that the fluorescent primers p2105.1:248-559， p2025.1:896-1059 and p2104.1:704-1015 designed by EST-SSR labeling showed good specificity in Ningxia Tan mutton， Xinjiang fine lamb and Tibetan mutton， indicating that the distinction of three sheep varieties was achieved. This study accurately judged the varieties of three pure-bred mutton through EST-SSR marker technology science， which was of important significance for the development and utilization of sheep genetic resources， variety identification and rich molecular marker types.