Children 6-15 years old with allergic rhinitis and/or asthma diagnosed by specialist physician are enrolled in the department of respiratory and otorhinolaryngology and pediatrics in Guangzhou Institute of Respiratory Disease. According to presence of typical symptoms and signs, patients are divided into allergic rhinitis without asthma (AR group) , allergic rhinitis concomitant asthma (AS+AR group), asthma without rhinitis (AS group). In addition, healthy students in a school are enrolled as normal control group. History of all subjects are collected, the following measurements are performed: skin prick test (SPT), peripheral blood cells five-classification test, serum total immunoglobulin E (IgE) and specific IgE of common inhalant allergens testing, nasal lavage and induced sputum cells classification ，pulmonary function test, bronchial provocation test using methacholine，airway resistance measured by impulse oscillation technique, the levels of eosinophil（ECP），eosinophil peroxidase（EPO）.Meanwhile myeloperoxidase （MPO）and eosinophil-derived neurotoxin (EDN) are measured in induced sputum ,in nasal lavage and in serum.
