This study was carried out in Mississippi, EUA, in 1977, with the purpose of comparing the effects of mechanical haverst and artificial drying on seed quality of soybeans having permeable (Dare) and impermeable (D-1) coats. Seed were harvested by combine and hand as soon as possible after maturity and after four additional weeks of field weathering. Only the mechanically haversted seed from the first harvest were used for the drying studies. The standard germination, TZ, accelerated aging and physical damage tests were used to evaluate the effects of the treatments on seed quality. Combine harvest lowered hard seed content to agronomically acceptable levels only when the seed were near 11% moisture content. Mechanical harvest, unexpectelly had no effect upon viability, but resulted in reduced vigor ratings. Seed having permeable seed coats germinated faster than those possessing the impermeable characteristic, however, this difference was reduced by the effects of mechanical harvest. The percent undamaged seed was higher for the D-1 seed at both harvest dates, despite the fact that these seed were 5,2% lower in moisture than the 'Dare? on the second harvest. Delayed harvest lowered viability and vigor ratings of the 'Dare' seed, but only vigor ratings of the D-1. This delay in combine harvest resulted in increased physical damage in both seed types. Artificially drying the D-1 seed increased hard seed content, but had no other immediate effect on quality. There was some indications of a direct relationship between seed coat permeability and rate of moisture loss.