In this paper, an attempt was made to establish the optimum propeller design method in non-uniform flow, especially considering unsteady cavitation. For that purpose, the optimization method of blade section profile was investigated, which was known to be closely connected with cavitation characteristics. Based on the following two ideas, a tentative design method was proposed, using the conventional MAU-propeller design chart and Koyama's lifting surface theory. (1) To adjust each r/R section's camber height so as to absorb the non-uniformity of wake in the radial direction. (2) To optimize each r/R section's thickness distribution so as to improve the chordwise unsteady cavitation characteristics. The propeller designed by this method was called NTR-type, and it was able to change its section profile against a given wake pattern. A conventional MAU-propeller and two NTR-propellers having different section profiles were designed for a certain wake pattern, which was expected to cause violent cavitation. And the following experiments were performed on these three propellers, to verify the design ideas of NTR-propeller, and to investigate the effects of the blade section profile on unsteady cavitation characteristics. (1) propeller open test and cavitation test in uniform flow (2) cavitation test in non-uniform flow (cavitation observation, cavity volume measurement, fluctuating pressure measurement, paint test, noise measurement) From these test results, it was verified that the cavitation performance of NTR-propeller was superior compared with that of the MAU-propeller. And the improvement of the blade section profile near the tip was found to be more effective in the reduction of fluctuating pressure amplitude.