The changes in moisture, cyanogen, crude protein and fat content of para-rubber seed at post-harvest from 0 to 27 days in August and 0-48 days in November were studied. After a short storage, 3 days in August and 6 days in November, the cyanogen content reaches its peak 230-250 mg/100g dry wt, then it decreases during the whole storage. Results show that reducing the initial drying rate promote cyanogen removal. Cyanogen content reduces more effectively in proper storage and processing, while crude protein content and fat content change little during storage.