Asthma is a complex and heterogeneous disease. We found gene-gene interactions between IL13 rs20541, IL4 rs2243250, ADRB2 rs1042713, and FCER1B rs569108 in asthmatic Chinese Han children. This 4-locus set constituted an optimal statistical interaction model. We examined associations between the 4-gene model (IL13, IL4, FCER1B, and ADRB2) and the Asthma Predictive Index (API) and atopy in Chinese Han children.