Objective To provide reference for the clinic doctors to choose inhalation drug and device rightly and teach the right way of inhalation to the patients by analyse the mastery of inhalation technique and the use of inhalation device in different age children with asthma.Mothods Observe and following direct the use of inhalation drug and device in 472 children with asthma at asthma outpatient department in our hospital during 2004.2-2008.7.The were divided into two groups,including the group(A group)who choose a right device and provided with specialized doctor to teach the method before the inhalation therapy,and no-provided with it(B group).Results The proportion of inhalation wrongly in A group and B group was separately 25.54% and 88.52%.there was a significant difference(P0.05)by÷~2 test.Following the use of inhalation device at 1 week,1 month after specialized doctor' direction in two groups,the proportion of wrong method was 16.84%、18.33%、6.79%、9.81%,no significant difference in two groups(P0.05).The proportion of wrong in the group directly using MDI at initially,1 week later and 1 month later was separately 88.38%,79.06%,67.44% though taught by specialized doctor.There was a significant difference compared with the group choosing right inhalation device before therapy(P0.05).In the group no specialized doctor direction,the common errors concluded the nose not mantled by the veil(22%),no shaking the aerosol before inhalation(18%)and no up toward the MDI(15.6%)in the patients using the MDI with a veil having a valve;The proportion of the nose not mantled by the veil was 16% in the patients pulverization using a pump by air drive;no gargle and washing after inhalation(12%);no inspiration deeply(14%);the time of hold the breath was less than 10 second after inhalation or exhalation by the nose at the same time(11%)in the patients using discus inhaler;no press the valve at the same time of inspiration(66%,no shaking the aerosol(16%),no gargle(12%)in the patients of directly using MDI.Conclusion Rightly choose inhalation drug and device according to different age,right direction by specialized doctor before therapy,and correct the following on schedule were the key to ensure the efficacy and right technique.