The development of wavy texture in startup flows of liquid crystalline polymers through a slit cell is examined to clarify the mechanism of this phenomenon, using a liquid crystalline solution of 50 w % hydroxypropylcellulose. The startup flow at a constant flow rate is generated by a piston moving at a constant speed. It takes a comparatively long time until the wavy texture appears, and the induction time decreases with increasing apparent shear rate. However, it is found that the apparent shear strain required for the onset of wavy texture is independent of the apparent shear rate except at low apparent shear rates. For the slit with 0.52 mm thickness the wide wavy texture is observed at the initial stage of the emergence of wavy texture, and after that the wavelength of the wide wavy texture approximately halves regardless of the apparent shear rate. Furthermore, it is suggested that a twisted structure of molecular orientation exists in the induction period. The results obtained in the present experiments imply that the long-range order elasticity contributes to the emergence of wavy texture.