In this work, growth, characterization and gas sensing performance of fiber like structure thin films of CdS by chemical bath deposition (CBD) technique using the reaction between cadmium sulphate, thiourea and NH3 in an aqueous solution has been reported. The films of were deposited at different pH (9, 9.5, and 10) onto glass substrate at 65 oC. Characterization includes a different analytical technique such as, X-ray diffaractogram (XRD), Field emission scanning electron microscope (FE-SEM) and energy dispersive X-ray analysis (EDAX). The films deposited for pH =10 was observed to be most sensitive (S = 79) to H2S for 5 ppm at 50 oC. The response and recovery time is 7 sec, 12 sec respectively. The results are discussed and interpreted.