Northern Qilian region, in which more than two hundred ore deposits or spots, including Baiyin, have been discovered, is an important VMS mineralization province in China. Except for Baiyin, however, no remarkable breakthrough has been made in exploration of large deposits. This is attributed to the fact that these ore deposits or spots occur in outcrop areas around the basin and no effective technique could be used to explore the covered area. After the geogas survey was adopted in ore exploration in Heihe basin in 1998, Laidoutan and Bailiugou orebodies were found under thick overburden. These results indicate that geogas survey, as a useful means for VMS deposit exploration, can play an important role in mineral exploration in the covered basin, and that Heihe basin is likely to have potential in finding a superlarge Baiyin-type VMS deposit. The authors suggest that further geogas survey should cover the whole basin to delineate the prospect areas in combination with other techniques such as geophysical exploration and soil mercury survey. It is hoped that the discovery of VMS deposits in Heihe basin will lead to a series of considerable breakthroughs in looking for VMS deposits in other basins such as Subei, Menyuan and Tianzhu in Northern Qilian region.