Abstract: Through test and research on fatigue crack growth rate da/dN of X52 thin-wall pipe product, including sample making, test principle and test procedure, growth rate da/dN of X52 thin-wall pipe's mother material and weld material are obtained in this paper. The test results can be available in analyzing service life of pipelines containing crack. It is pointed out simultaneously in this paper that correction needs making on the above-mentioned test results in analyzing the service life of pipelines containing crack which propagates along the pipe radial.