Abstract: The important problem worth consideration in passing through the active fault areas is how to protect pipelines from damage. Considering the very low mechanical efficiency of seizmic load, pipe materials are admitted into the elastic zone. Therefore it is up to a stress-strain relational expression to induce a discriminant to determine if pipelines through an active fault area need to be strengthened, that is, the main decisive factors are ΔL representing the change of the length of a pipline and ΔL: the magnitude of extension; At ΔL≤ΔL_t: (or ΔL_c the limit length change permitted when pipelines are pressed), anti-seismic measures can be neglected in such areas. At ΔL>ΔL_t, (ΔL_c), there arises the necessity of aseismic enforcement. Also dealt with in the article are the 10 preventive measures necessary to take for pipelines in active fault areas.