Objective To validate the significance of forced oscillation technique (FOT) for diagnosis of asthma by using it to measure respiratory resistance of adult asthma patients and healthy subjects. Methods Respiratory resistance was measured by a hand-held FOT device for 5 adult asthma patients and 5 adult healthy subjects, respectively. The variation of respiratory resistance with time was also compared by statistical analysis. Results The respiratory resistance measured by FOT varied periodically with time in all cases, with the respiratory resistance for asthma patients was (294.98±86.24) and for the healthy subjects was (151.9±39.20) Pa?s/L, respectively, showing significant differences in two groups. Conclusions FOT measurement results showed that asthma patients exhibited a greater magnitude and variability of respiratory resistance as compared to their healthy counterparts, which was in agreement with the conventional diagnosis. FOT can provide a novel method for detecting mechanical parameters of the respiratory system in clinic, and as an important reference particularly for the accurate diagnosis of lung dysfunction, such as asthma.