Biochemical composition, the rates of nitrogen excretion in the form of ammonia, amino acids and total nitrogen, and oxygen consumption of the shrimp Crangon affinis were measured at three temperature regimes $(7,;15,;and;25^{circ}C)$ and the variations were also determined for starvation periods (1-25 days). The composition of the major biochemical fractions was analysed into carbohydrate: $4.2\%,;protein:;68.6\%,;lipid:;7.0\%,;chitin:;6.3\%,;and;ash:;14.6\%,$ all expressed as percentage of dry weight. Molting frequency was lower at $7^{circ}C;than;25^{circ}C$ during the period of starvation, and during the same period the higher temperature was, body weight and body compositions the more decreased. Through all starvation periods $O_2$ consumption tended to decrease but total nitrogen tended to increase at any temperature regimes. The dominant form of excreted total nitrogen was ammonia-N at any temperature. From the O:N ratio it appeared that carbohydrate and lipid reserves were quickly exhausted (1-5 days), and that proteins were the substrates oxidized to meet the energetic requirements of C. affinis at any temperature. After 25 days of starvation the O:N ratio remained constant near a value of 8, which indicates that only proteins were being utilized at three temperatures. After 25 days of starvaion C. affinis excreted 23.01ug N/mg body nitrogen per day at $7^{circ}C,;32.97mu g;N/mg$ body nitrogen per day at $15^{circ}C,;and;44.81mu g;N/mg$ body nitrogen per day at $25^{circ}C$, and lost about 1.75, 2.47 and $3.29^{circ}C$ of body protein per day at 7, 15, and $25^{circ}C$ respectively.