This study was conducted to investigate the combined effects of VFA composition of rumen fluid and cold exposure on the general clinical view and ruminal fermentation characteristics in sheep. Each infusion group was subjected to either thermoneutral (20±2 ℃) or cold environment (2±2℃) for 4 days. The total infusate of nutrients was examined in sheep via the technique of continuous alimentation. Four adult Suffolk sheep fitted with a permanent ruminal cannula and a simple T-shaped duodenal cannula were used. A peristaltic pump was used to infuse the solutions of volatile fatty acid triglycerides (VFA-TG, triacetin: tripropionin: tributyrin) consisting of 70:20:10 (low propionin division: LP) and 50:40:10 (high propionin division: HP) on the basis of energy and minerals into the rumen, and casein solution into the duodenum. The results obtained are summarized as follows: 1. During the cold exposure (latter half of the infusion period), respiration rate decreased (P$lt;0.10), but heart rate tended to increase in the thermoneutral environment. And respiration rate had no significant difference between the levels of VFA-TG solutions (LP and HP division), but heart rate was higher in the HP division than in the LP division (P$lt;0.10). 2. In the HP division, rectal temperature was lower (P$lt;0.001) in the cold exposure than in the thermoneutral environment, but remained unchanged by the temperature treatment in the LP division. During the thermoneutral environment, rectal temperature was higher in the HP division than in the LP division (P$lt;0.01), but remained unchanged by the levels of VFA-TG solutions in the cold exposure. 3. Urine pH values maintained the value of the thermoneutral environment during the latter half of the infusion period, and was lower (P$lt;0.05) in the HP division than in the LP division. 4. Ruminal total volatile fatty acid (VFA) concentration tended to increase in the cold exposure compared to that in the thermoneutral environment, and did not affect with the levels of VFA-TG solutions. 5. In the LP division, molar percent of acetate was higher (P$lt;0.10), but molar percent of propionate was lower (P$lt;0.05) in the cold exposure than in the thermoneutral environment. As a result, the ratio of acetate to propionate (A:P ratio) increased more (P$lt;0.10) in the cold exposure than in the thermoneutral environment. In the HP division, molar percents of acetate, propionate and butyrate were not affected by the temperature treatments. The results showed that the A:P ratio was not affected by the environmental temperature treatments. However the ratio was increased in the LP division than in the HP division (P$lt;0.001). 6. Ruminal pH values was not affected by the temperature treatments, but was higher (P$lt;0.001) in the LP division than in the HP division. And ruminal pH values tended to be higher in the HP division than in the LP division. 7. Infusion of VFA-TG into the rumen caused a marked increase (P$lt;0.01) in ruminal TG concentration during the cold exposure (latter half of the infusion period), but it was not affected by the levels of VFA-TG solutions.