Abstract: The chemiresistive sensor for organophosphorus compound was prepared by electrochemical deposition, the deposition process of EDOT-OH monomer on interdigital electrode was studied by current-voltage curve of cyclic voltammetry and the number of scanning cycles was optimized to obtain sensor with suitable resistance. The comprehensive performances of the prepared sensor were investigated.Resultsshowed when the scanning cycles were 10, the suitable resistance of the sensor was 1 kΩ; that this sensor had high response rate, response stability, recovery rate and recovery percentage and good selectivity of gas, and could detect a mininum gas concentration of 2 ppm.