The aim of the research was to study the changes in rates of respiratory function in children with asthma exacerbation. The study involved 63 children aged 6 to 18 years with asthma of varying severity in the period of exacerbation. All children underwent complex clinical and instrumental examination including spirography and body plethysmography. Results of the study of respiratory function in children with asthma have shown that a change in speed and capacity indicators at most patients. And the most pronounced changes have been reported in patients who are not receiving adequate anti-inflammatory therapy. A comprehensive study of changes in the bronchopulmonary system in children during exacerbation of asthma have made it possible not only to diagnose the disease, but also to spend time correcting the prescribed therapy.