Efficacy and safety of regular treatment with procaterol and budesonide inhalation suspension for young children with moderate persistent asthma

INTERVENTION: GROUP B + P (budesonide + procaterol) Phase 1: 4 weeks Inhalation of the mixture of procaterol(0.3ml for >15kg, 0.15ml for <15kg) and budesonide inhalation suspension(0.25mg), twice a day, using jet nebulizer (PARI TurboBOY N,PALI LC Plus Nebulizer) Phase 2: 4 weeks after phase 1 Inhalation of budesonide inhalation suspension(0.25mg), twice a day, using jet nebulizer (PARI TurboBOY N,PALI LC Plus Nebulizer) GROUP B (budesonide) Phase 1: 4 weeks Budesonide inhalation suspension (0.25 mg), twice a day, using jet nebulizer (PARI TurboBOY N,PALI LC Plus Nebulizer) Phase 2: 4 weeks after phase 1 Continue method of Phase 1 CONDITION: Bronchial Asthma PRIMARY OUTCOME: Symptom free days (Sympton is cough and wheezing and dyspnea and sleep disturbance) SECONDARY OUTCOME: 1.Score of symptom (base on asthma diary); 2.Frequency of inhaled short acting beta 2 agonist (SABA) use; 3.Unscheduled hospital visits and emergency room visits because of asthma exacerbation; 4.Count of blood eosinophil at baseline and end of phase 1 (end of phase 2,if possible); 5.Level of blood serum cortisol at baseline and end of phase 1 (end of phase 2,if possible); 6.QOL test at baseline and end of phase 1 (end of phase 2,if possible); 7.exhaled nitric oxide (only the child can be examined); 8.PEFR:morning and evening (only the child can be examined); 9.Adverse events INCLUSION CRITERIA: 1.Children with persistent asthma ‐Age : children over six months under five years of age ‐Severity : moderate according to the criteria of JPGL 2008 2.Children who (whose parents) have given informed consent for participation in the present study.