Experimental study of incident flow angle effects on vibration behavior has been carried out on aluminum tube in parallel triangular tube bundle with P/D ratio of 1.375. Fluid elastic instability is the most fatal mechanism from all of the vibration mechanisms and therefore must be dealt with a lot of attention. Experiments were performed on low speed water tunnel with the velocity of water ranges from 0.3 m/s to 0.7 m/s. The experiments were designed in a unique way to study the effects of incident flow angle on vibration behavior. The monitored tube was mounted flexibly in an array of rigid tubes. Experiments were conducted on a flexible tube for different velocities ranging from 0.3 m/s to 0.7 m/s with different array rotated angles (0 to 90 degrees). It was observed that the vibration level was significantly high at 75 degree configuration as compared to other rotated angle configurations. Also it was observed that the damping response is dispersed with all positive values, indicating that there is no instability in the tube.