Hypocotyl-derived callus cultures of Brassica pekinensis cv. Chunseng were grown on Murashige-Skoog medium containing NaCl, Na_2SO_4 and mannitol to clarify the effect of salts on callus growth, proline accumulation and water relations. Na_2SO_4 was more inhibitory than NaCl when survival rate, growth and fresh:dry weight ratios of established callus were measured. Fresh weight in 0.25% NaCl treatment was more than twice as increasable in comparison to the same concentration of Na_2SO_4 or control. Proline concentration was increased on either salt, attained at highest levels at the 5th subculture, and fluctuated as affected by both salts or mannitol. Concentrations of redeucing sugars were sharply increased after 2 or 3 times of subculture and decreased by increasing subculture. The water and osmotic potential in callus reached a maximum negative value after two weeks in culture, regardless of salt type and mannitol and tugor remained relatively constant on both salt and mannitol treatments.