Experimental investigation of mode conversions of a guided wave in a pipe through an elbow has been carried out. Based on the particle displacement of the guided wave modes, the mode conversions from the T(0,1) mode to circumferentially higher order modes, the T(1,1) and T(2,1) modes, were confirmed. The experiments were carried out with 8 sensor elements located circumferential positions to detect the modes. A simple signal processing method for preferential detection for each mode was shown.