Abstract: Objective To establish a standard technique on passaging Trichinella isolates for the purpose of teaching and scientific research. Methods Healthy mice were orally infected with muscle larvae of Trichinella isolates， and mice were killed at 40 days post infection. The weighed muscles of mice were minced into small pieces and digested by artificial gastric juice. The minced muscle tissues were incubated at 37 ℃ for 4 to 6 hours. The larvae were collected from the supernatant after appropriate filtration and differential sinking. The morphology of Trichinella isolates was observed by the microscope. Result The worms curled tightly like spiral in the microscope. Infectivity of Trichinella from swine and dog, T.spiralis and T.nativa in mice was significantly different （P<0.01）. Swine isolate and T.spiralis were highly infective to mice with RCIs of 121.01 and 149.86 respectively. However, mice was relatively refractory to dog isolate and T.nativa with RCIs of 60.98 and 55.15 respectively. Conclusion The effect is fine to passage by the way of digestion, and it can be preserved enduringly.

Key words: Trichinella isolates, Passage, Technique