Abstract: To study the effects of arc light and laser vision sensing weld pool oscillation signals under different welding condition for pulsed GTAW, the system that can obtain arc light intensity with the data acquisition card and collect the projected images with the CCD camera was built for detecting weld pool oscillation frequency in pulsed GTAW, and the comparative analysis about the sensing effects of two methods was carried out. From the experimental results, the quality of signals obtained by two different detection methods for a stationary weld pool shows good cohere; the arc light signal with the travel speed increasing become poor, but increasing travel speed has few effect on the quality of signal obtained by laser vision method. Thus, the method based on laser vision is suitable under traveling welding.