Abstract: Most of the west Tianshan and Kunlun-Aerjin mountains are high-and-cold regions,with greatly dissected land forms.The aero-magnetic survey of 1:1 000 000 scale has been finished and a great deal of magnetic anomalies obtained,showing that there is a good prospecting potential in mag netic deposits.But according to the Aero-magnetic survey specification,the flig htaltitude of aero-magnetic survey of 1:50 000 scale is less than 250 mabove the ground,which limitaero-magnetic survey of larger scale such as 1:50 000 to be executed.In order to promote the application of 1:50 000 aero-magnetics in these regions, first some direct problems were calculated according to classical deposit models of different depths and scales,and some practical survey were executed in 3 classicaliron deposits in differentaltitudes so that the results support the execution of 1:50000 aero-magnetics in these regions.The 1:50000 aero-magnetic survey were executed in 3 different geological,geophysical,and geography districts.The results show that there are clear magnetic field character istics,lower backg round changes,and obvious local anomalies under the high magnetic survey precision.