Abstract: The principle reasons for no large- and middle- scale natural gas fields with high yield and high enrichment up to now have been found in Junggar basin could be lack of large- scale traps with great thickness and good quality of gas reservoirs as well as high closure and big closed area. The study shows that the fundamental distri bution regularities of the gas reservoirs are as fallows:①The geographic and stratigraphic distribution of gas pools are obv iously controlled by the gas source region, showing that natural gas is much more closely distribution nearby the source region than crude oil;②Normal structures like arch stretching hydrocarbon source region should be main accumulating area;③It is faulting connected with gas source that controlled gas pool's distribution;④Regional cap rock and reservoir rock determined its profile distribution. Based on these knowledge, this paper presents the principles that should be followed and favorable exploratory directions for gas prospecting in Junggar basin. It is believed that these large scale anticline structures such as Mosuowan, Dongwan and Mahu anticline should be as important targets for the gas exploration.

Key words: Junggar basin, gas reservoir, geologic characteristics, trap, reservoir, cap rock, fault