Bronchial asthma is caused by a variety of cells (such as eosinophils, mast cells, T lymphocytes,neutrophils,airway epithelial cells)and the cellular components involved in chronic airway hyperresponsiveness, and inflammatory diseases. Cytokines, adhesion molecules and some newly discovered inflammatory mediators have become the focus of research. Under normal conditions, the expression and secretion of cytokines are tightly controlled by the body. In pathological conditions, cytokines and their receptors are defective and cytokines are expressed too high or too low. Cytokines secrete and regulate the immune response. And they promote or inhibit each other in the immune response,and reach a balance state.