A phosphate-sensing chip was constructed by a copper phosphate-deposited electrode. The modification of ionic liquidplasticizer can improve the selectivity of phosphate anionsreduce the interference of sulfate, nitratechloride anions. The sensing chip equipped with a portable electrochemical device can directly detect the phosphate concentration of solution extracted from soil samples in ten minutes by using amperometry. The sensing chip promises the feasibility of detecting the phosphate concentration without expensive instrumentlabor-intensively chemical colorimetry.