Objective To investigate the cytokines including IL-5,IL-4,IL-13 and thymic stromal lymphopoietin (TSLP) levels of Th2 immune response to Paragonimus infections,thus to find the potentialbiomarkers for clinical diagnosis on parasitic worms infections.Methods The sera of local paragonimiasis patients from adult ( ＞ 18 years old) and juvenile ( ≤ 18 years old) group in Guizhou Province were collected,respectively.The concentration of IL-5,IL-4,IL-13 and TSLP was measured by ELISA and analyzed with independent sample t test among each patient group and control group.Simultaneously the epidemical data of patients were investigated.Results The concentration of IL-5,IL-4,IL-13 and TSLP in adult group was (9.50 ±5.57) pg/ml,(0.95 ±0.19) pg/ml,(475.30 ±629.81) pg/ml and (16 676.67 ±7 169.29) pg/ml,respectively while in juvenile group was (23.04 ± 3.37) pg/ml,(1.05 ± 0.19) pg/ml,(422.84 ± 539.48 )pg/ml and (16 242.50 ± 6230.81 ) pg/ml,respectively.Meanwhile the concentration in control group was (4.45 ±0.84) pg/ml,(0.32 ± 0.12) pg/ml,(41.15 ± 11.72) pg/ml,(490.00 ± 123.36) pg/ml,respectively.IL-13 and TSLP increased significantly in two patient groups (t =1.27,P ＜ 0.05; t =3.11,P ＜0.05).IL-5 increased significantly in juvenile with typical paragonimiasis epidemiology features (t =3.11,P ＜0.01 ).On the contrary,IL-5 had no significant change in adults without typical symptoms (t =1.52,P ＞0.05).The variation of IL-4 in two patient groups had no statistical significance ( t =1.08,P ＞ 0.05 ; t =2.1,P ＞ 0.05).Conclusion Th2 immune response was activated in paragonimiasis patients with significant up regulation of IL-5,IL-13,and TSLP.The cytokines are of worth to be further researched and screened as potential biomarkers.