Six salt tolerant rice lines, RD23TC4, RD23TC7, RD23TC28, RD23TC75, RD23TC95 and RD23TC110, which were somaclonal varieated lines and obtained from The New Varieties of Rice for Saline and Acid Soil through Tissue Culture Project, Unit cell of Plant Tissue Culture, Chulalongkorn University, were used to studied the proline and sugar accumulation during salinity and drought stress, with the comparison to the original rice line, RD23. Growing in the nutrient solution, supplemented with 0.5% NaCl (9 mmhol/cm EC) the original rice line, RD23, showed the survival rate of 5.3%, while the other salt tolerant lines survived at the rate of 22.66-55.00%. When the salt tolerant lines were grown in the nutrient solution, supplemented with lower concentration of NaCl, 0.3%, the survival rates were higher, ranging from 63.33-74.66%. Under drought stress that caused the original RD23 to have the survival rate of 5.3%, the salt tolerant lines showed the high survival rates up 62%. Both salt and drought stress made all rice lines accumulate higher levels of proline and sugar, compared to the accumulation level at normal condition. However, the salt tolerant lines could accumulate both proline and sugar in the significantly higher levels than the original rice line in both stress conditions.