Muscle larvae of Trichinella spiralis were isolated by digestion method,the cells were separated through homogenization,the primary cells were cultured in RPMI-1640 medium containing 10% fetal bovine serum,and passage cultivation was carried out after trypsin (containing 0.02% EDTA) digestion.The cellular ultrastructure was observed by using transmission electron microscope,and the cultured cells were identified by multiplex PCR.The results showed that the primary cells began to adhere to the bottom of culture flask 24-72 hours after inoculation.The cell monolayer formed 7-8 days after culture,and distinct fusion among cells was not observed.Each passage could be completed within 10-12 d.The results of transmission electron microscopy showed that the cell nucleus of T.spiralis muscle larvae was elliptic.There were clear karyotheca,nucleolus and abundant chromatin in the nucleus,and plentiful mitochondria in the cytoplasm.There were mainly two types of cells:elliptic and polygonal cells,and most of them were elliptic.The DNA extracted from the cultured cells was amplified by multiplex PCR and the band (173 bp) was the same as the DNA from T.spiralis muscle larvae.The results show that the passage cultivation of T.spiralis muscle larval cells could be maintained in RPMI-1640 medium containing 10% fetal bovine serum.