The regional pattern for ecological security (RPES) is a new concept

and its theory is under development. To solve the problem of pipeline safety and the ecological destroy

the paper put the theory into use in the Shannxi Section along the West-East Gas Pipeline Project

and put forward the design framework for the RPES along the pipeline. The mapping analyze shows that there are mainly 7 ecosystems including rolling hill/loessial soil/farmland ecosystem

rollinghill/loessial soil/hassock grass steppe ecosystem

plain/loessial soil/farmland ecosystem

sandy land ecosystem etc. Sensitivity analyze of soil and water loss shows that over 80% of the region is the sensitive region

which is the character of the severe loss of water and soil. 6 key ecological units are given in the long loess ridge and round hill

the area of terrene bridge between two hills (Yaoxian)

the area crossing the middle and small gully

open-riverbed-ditching

around the area of concave bank of River by WEPP in loess hilly area along WEPP.At last the security pattern designs are focused on the ecosystems and key ecological units.