Abstract: Objective  To establish the technique of isolation and culture of lung fibroblasts from Microtus fortis in vitro, and observe the killing effect of lung fibroblasts on schistosomula.  Method  The shape and growth characteristics of lung fibroblasts, isolated from new-born Microtus fortis at the ages of 1, 3 and 5 days and cultured in DMEM and RPMI 1640 culture media respectively, were observed by inverted microscope after tissue adhering and trypsin digesting. The mortality rate of schistosomula was counted after co-culturing with the supernatant of 2nd and 3rd generation of Microtus fortis lung fibroblasts（MfLF）for 96 h respectively, and the schistosomulum-killing effect was observed by inverted microscope.  Results  The fibroblasts grew well by using tissue adherence method. MfLF cultured in both DMEM and RPMI 1640 media showed no difference. One to 3-day-old rats revealed better cell viability and purity. HE staining showed that the MfLF had an oval-shape nucleus and was passaged 4-5 times only in vitro. The culture supernatant of the second and third generations MfLF caused 9.5% and 10.5% death rate of schistosomula in 96 h respectively, with no significant difference to the negative control（8.8%）.  Conclusion  The tissue adherence method developed is suitable for culturing the lung fibroblasts of M. fortis but the culture supernatant shows no effect in killing schistosomula.

Key words: Microtus fortis, Lung fibroblasts, Schistosoma japonicum