The partial pressures, p(Cd) and p(Zn), over Cd1-xZnxTe (CZT) and Cd1-xZnx, melts were estimated based on known thermodynamic data and the partial pressures, p(Cd) and p(Zn), over Cd0.86Zn0.14 alloy melt at a temperature of about 980 degrees C could be equilibrium with those over Cd0.8Zn0.2Te melt at a melting temperature of 1162 degrees C. The Cd0.8Zn0.2Te crystal growth from the melt under controlled constituent partial pressures, provided by Cd0.86Zn0.14 alloy instead of only Cd source was carried out in this work. The best result for the resistivity, which has reached up to about 10(10) Omega cm, has been obtained under the equilibrium partial pressures estimated by thermodynamic relationships. The axial variation in Zn concentration, which has been obviously improved due to the Zn replenishment from the reservoir during the whole growth procedure, is within about 4%. EPD on the average was about 2 x 10(5) and 4 x 10(4)cm(-2) at the middle of the bulk. IR transmissivity in the range of 2 to 42 mu m is larger than 60%. In addition, the relationship between resistivities and conducting types of the crystal and different controlled pressures is also discussed.