The effect of water extracts of Pu-Erh tea (products of Yunnan district, China, preserved for 2 or 20 years) and of green tea (products of Shizuoka prefecture, Japan) on lipid level, tissue weight, lipoprotein lipase (LPL) and adrenalin-induced lipolytic (AIL) activity in rats were examined. Female Wistar rats (8 weeks old) were fed a diet containing 1% cholesterol and given the above tea extracts in drinking water for 8 or 16 weeks ad libitum. The levels of plasma cholesterol ester in rats given Pu-Erh tea or green tea were significantly lower than those of control rats after 6-8 weeks, though the difference became smallar after 10 weeks. The triglyceride (TG) level in plasma was also low in rats given Pu-Erh tea for 16 weeks. This effect on TG was not observed in the case of green tea. Among 6 organs or tissues of rats examined, the weight of abdominal adipose tissue was significantly lower in rat fed Pu-Erh tea for 16 weeks. The LPL activity in abdominal adipose tissue tended to be low (though not statistically significant), while the activity of AIL was significantly elevated in rats given Pu-Erh tea for 8 or 16 weeks. A negative correlation was observed between AIL activity and the ratio of adipose tissue/body weight. These data suggest that the successive administration of Pu-Erh tea could stimulate the degradation of TG in adipose tissue and thereby decrease its weight.