The Polycrystalline (CdSe)1-x(ZnS)x semiconductor powder with 0<=x<=1 was prepared by controlled co-precipitation method. Pellets made out of the powder, sintered at 800o C in nitrogen atmosphere was used for studies. Electrical conductivity of these samples increased with increasing the temperature from 77-300o K. At a given temperature an increase in conductivity with the increase in composition was observed in samples with x = 0.2 to 0.4 where as decrease in conductivity with the increase in composition occurs in samples with x = 0.7 to 1. For all samples, activation energies were calculated from the linear portions of log s vs 1000/T and the values range between 0.021 eV to 0.042 eV measurements of all samples are found to be negative, indicating n-type conduction in temperature region 77-300oK.From TEP and conductivity studies, carrier concentration and their mobilities were deduced and all the results were reported and suitable reasons were attributed for each observation made.