We report the formation, destruction, and re-formation of the microcrystallites in a chemical PVA gel, crosslinked slightly by glutaraldehyde. The dried gel, in which the microcrystallites were formed, was immersed in a poor solvent of a mixture of DMSO and water at 8 A degrees C, where the gel stayed in its collapsed state. The gels swelled on heating to 50 A degrees C, but did not return to the initial state on cooling to 8 A degrees C. After washing the gel completely in water, a drying process caused the microcrystallites to be re-formed and the gel could return to the initial dried state at 8 A degrees C. By using XRD and FT-IR measurements, it was concluded that the formation and destruction of microcrystallites in chemically crosslinked PVA gels could be controlled by the mild treatments of initial drying, temperature change, and washing and drying.