Abstract: The effect of attenuation on inspection range was studied experimentally by using the magnetostrictive ultrasonic guided wave technology, aiming to help the pipeline manager to assess the rang of inspection and the price of inspection, and to make proper inspection plan before carry out guided wave test, because the pipelines in complicated surroundings can cost more inspection time and inspection price. First, the relationship between attenuation and inspection range had been researched, then the range of inspection under known value of attenuation coefficient could be calculated. Three pipeline inspection experiments were undertaken in different surroundings (above ground pipeline, half-buried pipeline and buried pipeline). The experimental result shows that high attenuation strongly affects the range of inspection and a significant change in the attenuation coefficient and inspection range exists for different surroundings.