Patients with chronic obstructive bronchitis showed an increased activity of the blood plasminogen activator in a group of patients under 40 years of age and absence of the dynamics of this index an older age group. The urokinase urinary activity did not change in the two groups. The blood activator activity increased in healthy young non-trained and trained young persons under the effect of loads. The urinary urokinase activity reduced only in trained persons.