Objective To observe the immunoglobulin A secreting cells (IgASCs) and secretory IgA (sIgA) level in jejunum of mice infected with plerocercoids,and to understand the roles of resistance to invasion processes of the plerocercoids.Methods A total of 100 Kunming mice (half males and half females) were chosen,the weight was 20-25 g,they were randomly divided into control and experiment groups according to their body weight via the random number table method,50 per group.Mice of experiment group were fed each with 5 plerocercoids in snakes,and mice of control group were not infected,testing time and methods were the same in the two groups.Ten mice were randomly sacrificed from one group on days 1,7,14,28 and 56 after infection,to collect empty intestinal juice and jejunal segment.The immunohistochemical method was used to examine the quantity of IgASCs in jejunal mucosa,while enzyme-linked immunosorbent assay (ELISA) was applied to test the level of slgA of jejunal fluid.Results The IgASCs were distributed in lamina propria of the jejunal mucosa,and the percentage of positive IgASCs reached the peak value [(64.24 ± 0.60)％] at d 1 after infection in experiment group,then decreased,and it was lower than control group at d 14 [(41.98 ± 0.42)％ vs (43.52 ± 0.94)％,t =-4.727,P ＜ 0.01].The sIgA level reached the peak value [(22.05 ± 1.43) mg/L] at d 7 after infection in experiment group,then decreased,and there was no statistical significant difference between control and experiment groups at d 56 [(20.00 ± 0.42) mg/L vs (21.26 ± 2.59) mg/L,t =1.516,P ＞ 0.05].There was a positive correlation between the percentage of positive IgASCs in the jejunal mucosa and sIgA level in the jejunal fluid at d 7 after infection (r =0.663,P ＜ 0.01),and there was a negative correlation between them at d 14 after infection (r =-0.542,P ＜ 0.05).Conclusion The plerocercoids infection might induce high level expressions of IgASCs and sIgA,they show positive correlation at d 7 after infection.