OBJECTIVE: To study allergens and their relationship to the occurrence of childhood bronchial asthma in the Jiading District of Shanghai. METHODS: Three hundred and eighty-two 4 to 12-year-old children with asthma in the remission stage from Nanxiang Hospital in the Jiading District of Shanghai were used as a case group (asthma group), and 402 children from two primary schools and two kindergartens in Jiading were enrolled by cluster sampling and served as control group. Parents of the children completed a questionnaire on living conditions and allergy-related disease history. Skin prick test (SPT) for 18 common allergens was carried out in both groups. In order to examine the effect of environment and living conditions on SPT results, children in the control group were further divided into two sub-groups according to birth place: migrant (219 cases) and resident (183 cases). RESULTS: SPT results revealed that the main allergens identified in the Jiading region were dermatophagoides farinae, house dust mites, shrimps, cockroaches, and dog hair. The SPT positive rate was 67.9% in the asthma group, and this was significantly higher than in the control group (31.8%) (P<0.01). The environment and living conditions in the migrant group were significantly different from the resident group (P<0.01), whereas the SPT positive rate for this group was significantly lower than in the resident group (P<0.01). CONCLUSIONS: Allergens in the Jiading region mainly originate from dermatophagoides farinae, household dust mites, shrimps, cockroaches and dog hair. Children with asthma are more susceptible to allergens. Environment and living conditions may be relevant, to a certain extent, to an SPT positive rate.