Abstract: HI-101 portable spirometry produced by Japan Jester company, can measure the vital capacity, forced vital capacity and the maximum ventilation, which is widely used in the occupational health examination, occupational disease diagnosis and the respiratory system diseases diagnosis. The author is engaged in the pulmonary function testing for many years. After repeated practice, we summarize the using skills of HI-101 instrument and common problem treatment experience, which will share to pulmonary function detection of physicians on the job.