Abstract: In this paper, cold water irrigation multiplication technique was used to solve the difficulty of multiplying rice TGM Sline 96-5-2S(Oryza sative L.) with double low critical temperature values under natural air temperature condition. The results indicated that irrigating rice TGMS line 96-5-2S with different temperature underground cold water from the stage of pistil and stamen primordia differentiation to the stage of pollen filling for 15 days, and keeping the water depth 18～22 cm, the seed set rate of 96-5-2S decreased with increasing irrigating water temperature. When the average temperature of irrigation water was 18.5～19.8 ℃, the seed set rate ranged from 40.5% to 57.6%, and the yield ranged from 3.30 t·hm^-2 to 4.35 t·hm^-2.While the temperature was 20.5～21.3 ℃, the seed set rate and yield sharply decreased to 2.5～10.4% and 0.21～0.90 t·hm^-2, respectively. When the average temperature was 22.3～23.5 ℃, both the seed set rate and yield were zero. Under the same irrigation water temperature (average 19.8 ℃) and the same irrigating period (phase Ⅳ to phase Ⅶ), the seed set rate and yield of 96-5-2S with deep water irrigation (18～22 cm) was very significantly higher than those of 96-5-2S with shallow water irrigation (7～10 cm). Under the conditions of same irrigation water temperature (average19.8 ℃) and same water depth (18～22 cm) but different irrigating periods (15 days from phase Ⅳ to phaseⅦ, 20 days from phase Ⅲ to phase Ⅶ, and 25 days from phaseⅡ to phaseⅦ), the difference of seed set rate and yield of 96-5-2S between15 day treatment and 20～25 day treatment was not significantly different. It is confident that 96-5-2S could multiply with underground cold water irrigation. The main technique index was that irrigating water temperature should be 18～20 ℃,irrigating period should be from phase Ⅳ to phase Ⅶ, and irrigating water depth should be 18～22 cm.