The torsion tests in the range of $550~800^{circ}C$, $5.0{ imes}10^{-3}~5.0{ imes}10^0/sec$ were performed to study the effects of strain rate$(.{varepsilon})$ and temperature(T) on the hot strength of Cu-Zn alloy. High temperature flow stresses of this alloy increased with increasing $.{varepsilon}$ and/or decreasing T, and than the more grain refinement could be obtained. The flow curves exhibited a peak followed by a steady steady state regime as a result of dynamic recrystallization. The hot strength dependence of $.{varepsilon}$ and T was described by a hyperbolic sine law, $.{varepsilon}=A(sinh0.017{sigma})^4.81$exp(-216KJ/mol). Hot strength could be reduced at the arbitary condition, $.{varepsilon}$ and T, by constitutive parameter Z(Zenner-Hollomon parameter), $Z=A(sinh{alpha}{sigma})^n=.{varepsilon}$exp(Q/RT).