Asthma is the most common chronic disease of childhood and one of the most difficult conditions for clinical pediatricians to diagnose definitively in infancy and early childhood. more than 50% of wheezing symptoms occur before the age of 3 years. However, only about 30% of all wheezing children with recurrent wheezing are still asthmatic by age 6 years. In order to avoid misdiagnosis and underdiagnosis, a large clinical study was conducted more than 10 years ago by foreign experts. The study was conducted on 1,246 children enrolled in a multi-year follow-up until the age of 13 years and predicted the risk of asthma in school age based on factors associated with the first 3 years of life. Based on the results of the study, the Childhood Asthma Prediction Index was proposed, and four years later a revised API was developed, which was incorporated into the Guidelines for the Diagnosis and Prevention of Bronchial Asthma in Children in China and considered to be effective in predicting the risk of developing persistent asthma in wheezing children within 3 years of age. Specifically, the following: ≥4 wheezing episodes in the past 1 year with 1 major risk factor or 2 minor risk factors. The primary risk factors included: 1. parental history of asthma; 2. physician-diagnosed atopic dermatitis; 3. evidence of inhalation allergen sensitization. Secondary risk factors included: 1, evidence of food allergen sensitization; 2, peripheral blood eosinophils ≥ 4%; 3, wheezing unrelated to cold.