We have studied 140 patients with bronchial asthma by questionnaire on family anamnesis, complications, past history, onset of asthma attack, seasonal variation and precipitating factors. 1. Among close relatives of the patient, those with asthma were found in 68.6% and those with any type of allergic disease in 78.6%. 2. Allergic rhinitis was seen in 57.1% of the patients as complication, 28.6% of them had asthma in childhood and 76.4% any type of allergic disease. 3. Important provocation factors of the initial attack seemed to be coldness and weariness. The period of remission was long term in 12 cases(6- 44years). 4. Asthma attack occured more frequently in autumn and spring. Attack has remarkably decreased during the period between June and August, which is longer than in the main land of Japan. 5. It was noted that change of the climate such as coldness, cloudy weather before rain etc, dusts, overwork, physical exertion, exhaustion, overeating, drinking and smoking could be common precipitating factors.