An experiment was conducted at Department of Plant Science, Faculty of Natural Resources, Prince of Songkla University, Hat Yai, Songkhla, during January-April, 2005 to study seed development andmaturation in common bean (Phaseolus vulgaris L.). At flowering, the flowers were tagged to indicate the date of flowering. Seeds at 10, 13, 16, 19, 22, 25, 28, 31 and 34 days after flowering were harvested to investigatepod color and seed quality. The results showed that common bean had 4 developmental stages of pod color: green at 10-22 days after flowering, yellow at 25 days after flowering, grey-yellow at 28 days afterflowering and yellow-white at 31-34 days after flowering. The common bean seeds were capable of germination at 16 days after flowering with seed dry weight of 112.00 mg/seed, moisture content of 68.30% and thestandard germination of 29.50%. The seeds reached physiological maturity 28 days after flowering with maximum dry weight of 218.38 mg/seed, moisture content of 24.44%, standard germination of 99.00%, soilemergence of 98.50%, with highest speed of germination index and seedling growth rate and lowest conductivity. Common bean pods harvested for seed production should be at greyed-yellow color stage with blackcolored seeds.