The gas sensors fabricated by using conducting polymer (P3HT), the poly (3-hexylthiophene)(P3HT) prepared by chemical polymerization of 3-hexylthiophene at room temperature and under inert atmosphere of N2, using hexahydrate ferric chloride as oxidant. A chemical sensor was prepared by deposition of polymer films in two techniques (Dip-coating and Spin-coating). The sensors demonstrated ppm level sensitivity and good sensitivity to various volatile organic compounds (VOCs) such as methanol, ethanol, chloroform, toluene and hexane, in concentration range of 8000-640000ppm. Direct comparison of the two sensor films with respect to sensitivity, response time and recovery time was made by measurement of the resistance changes upon simultaneous exposure to each analyte, electrical measurements showed highest sensitivity, response time and recovery time lower in technique Spin-coating compared with Dip-coating, this means the technique Spincoating is better than Dip-coating. sensitivity decreased with sensors P3HT temperature increase in the range between 250C and 700Cin the two techniques.