Two asthma calssification systems associated with the pathophysiology of the airways were evaluated in 30 adult patients with bronchial asthma. The systems were classification by clinical symptoms (clinical diagnosis) and classification by a score calculated from clinical findings and examinations (score diagnosis). Thirty subjects were classified into 15 patients with Ia. simple bronchoconstriction type, 6 with Ib. bronchoconstriction+hypersecretion type and 9 with II. bronchiolar obstruction type by clinical diagnosis. Fifteen subjects with type Ia comprised 10 patients with expectoration of 0-49 ml/day and 5 of 50-99 ml/day. The patients with expectoration of 50-99 ml/day were classified as type Ib by score diagnosis. The value of FEV1.0% was significantly lower in patients with type II than in those with type Ia. The value of % V25 was significantly lower in patients with type II asthma compared with type Ia and type Ib subjects. No significant difference was observed in the values of % FEV1.0% and % V25 between patients classified by clinical diagnosis and score diagnosis. The proportion of neutrophils in BAL fluid was significantly higher in patients with type II compared to those with types Ia ad Ib by both classification systems. The proportion of eosinophils in BAL fluid was significantly higher in types Ia-2 and Ib by clinical diagnosis and in type Ib by score diagnosis than those classified as type Ia-1 by both systems.