A novel composite material composed of inorganic semiconductor antimony sulphide (Sb2S3) and organic semiconductor copper tetra-beta-(4-carboxyphenoxy) phthalocyanine (CuT beta Pc) was prepared by a simple solution deposition process. The crystallite structure and properties of Sb2S3-CuT beta Pc composites were analyzed by XRD, SEM, FTIR and UV-vis. The electrochemical behavior of the sensor was investigated using cyclic voltammetry (CV) and amperometry. For the development of a potential chemical sensor, Sb2S3-CuT beta Pc composites were deposited on flat platinum disk electrodes to give sensors that responded quickly and selectively to hydrazine in phosphate buffer phase. The hydrazine sensor showed a linear detection range from 10nM to 0.5 mu M and detection limit of 0.9nM at a signal-to-noise ratio of 3. Thus this novel composite may be potentially applied in the field of catalysis and environment.