Using introduced near-surface geochemical prospecting system, we collected, ana-lysed, processed and interpreted geochemical data in Caoqiao oil field on the southern slope of Dongying depression in Jiyang downwarping region. Studies show that this system has obvious technical advantages in data collection and on-the-spot quality control. With this system, faults, oil-water boundaries and pinch-out lines of oil beds in known oil fields all exhibit obvious geochemical anomalies. Through experimentation with various methods, a preliminary investiga-tion was conducted on longitudinal and lateral variation in abundances of hydrocarbon materials.