Abstract: Objective To test the levels of IL-4,IL-12 and IFN-γ in nasopharyngeal aspirates(NPS) of infants with wheezing,and to explore the relationship between the infantile wheezing and the type of cytokine response. Methods The NPS of IL-4,IL-12 and IFN-γ levels were measured by ELISA and compared in 58 cases of acute stage and convalescent stage with infantile wheezing and 47 cases of infantile pneumonia. Results The NPS of IFN-γ levels in acute group[(142. 55 ±26. 56) ng/L] were significantly lower than(275. 11 ±30. 27) ng/L of the infantile pneumonia group,(253. 76 ±39. 9) ng/L in the control group and(260. 88 ±28. 07) ng/L in the recovery group,P < 0. 01; while the IL-4[(8. 51 ±2. 02) ng/L,(3. 14 ±1. 16) ng/L,(4. 95 ±1. 93) ng/L,(3. 28 ±1. 36) ng/L] and the ratio of IL-4/IFN-γ(0. 068 ±0. 044,0. 012 ±0. 004,0. 019 ±0. 007,0. 014 ±0. 005) were significantly higher(P < 0. 05); Compared with the infantile pneumonia group[(1 322. 13 ±139. 74) ng/L],the acute group's IL-12 level[(587. 24 ±58. 14) ng/L] in NPS were significantly lower(P < 0. 01) and no statistical difference with the recovery group[(580. 77 ±64. 32) ng/L]and the control group[(604. 02 ±88. 38) ng/L],P > 0. 05. Conclusion The acute Stage of wheezing in infants are with the Th2-predominant response,increase of IL-4 level,decrease of IFN-γ level in NPS,and IL-12 increase in infantile pneumonia.