The instability of flow induced structure of liquid crystalline polymer solution has been investigated in two dimensional channel flows. The influence of round off curvature at a corner on the unstable behavior after a flow direction change has been mainly examined. The orientation angle and the dichroism were measured with a laser optical measurement system. The unstable behavior of liquid crystalline polymer solution has typical periodic oscillatory characteristics, and the periodic motion became larger toward the downstream from the corner. The increase in periodicity was significant at the inner side of the channel. The larger round off of the corner suppressed the periodic motion, so that it is considered that the shape of the corner is one of the causes of the instability.