Recruit 30 children with asthma and 30 healthy children based on the consent of the children and their parents or their guardian. Collect and record general information such as name, age, time of first diagnosis, allergens or triggers, daily dosage and frequency of asthma control drugs, home address and contact information. Collect 5 ml of blood sample for the detect of the biomarkers. Asthma severity was assessed using pulmonary function by spirometry and score of C-CAT. Finally study the correlation between the level of biomarkers and asthma severity and the role of biomarkers in the occurrence and development of asthma.