Abstract: It is necessary to be in the know of the geological features and general configuration of the loess before laying long distance oil/gas pipelines in loess area. The loessial lands in Northwest China are all of Quaternary accumulational matters mainly consisting of such minerals as quartz, feldspar and calcite, with the land-forms being plain, ridge and dune. Pipeline shall be laid following the principles as below: going with the level and stable surface of the land; extenting along the contour line; avoiding scoured sections having serious landslip and soil and waler loss, as well as deep gully sections; meeting the comprehensive requirement of safety, reliability and economic feasibility. Duing construction, such measures as flood control and draining, rational line pipe selection, local reinforcement of foundation, etc. shall be taken to prevent the effect of collapsible soil on pipeline. Safe operation can be guaranteed in the section having serious water and soil loss by taking the combined measure of pile driving at the end of ditch and vegetation planting.