Abstract: Based on the sound intensity, a method of frequency-shift-compensation of sound intensity spectrum is used to estimate waveguide invariant and source range. When one of the waveguide invariant and range is known, this method can be used to estimate the other. With this method, waveguide invariants at different ranges are estimated experimentally using LFM signals radiated by one towed sound source and received by one sea-floor located horizontalline-array in the Yellow Sea in December 2011. It is shown that waveguide invariant varies from 0.8 to 1.2, whose mean value is near the theoretical value invariant, which are in agreement On the other hand, ranges are estimated using the theoretical value of the waveguide with the ranges measured by GPS.