Enhancement of glycerol production in Shochu yeast, which was induced by heat-shock treatment, was studied. Although heat-shock treatment (45°C, 1 h) caused a transient delay in cell growth, the amount of glycerol produced by heat-shock-treated cells was 20% higher than that by control cells. During the glycerol-production phase, the NAD +-dependent glycerol-3-phosphate dehydrogenase (GPDH) activity of heat-shock-treated cells was much higher than that of control cells, suggesting that a higher GPDH activity enhances glycerol production. The level of NAD +-dependent glycerol dehydrogenase (GDH) activity was almost the same between heat-shock-treated cells and control cells. The results of Northern blot analysis of GPD genes ( GPD1 and GPD2) encoding the GPDH enzyme showed that the transcription of GPD genes was not affected by heat-shock treatment but the period of intensive transcription of GPD1 was prolonged.