To elucidate the effect of temperature on the fruit body growth and structure of pleurotus ostreatus cultivar Chunchu No.2, microstructures were observed with scanning- and transmission electron microscope. Pileocystidia were well developed on the surface of pileus in the fruit body cultivated at $7^{circ}C$. As the increasing temperature for fruit body development, thickness of pileus, thickness of stipes and length of stipes shown thin, thick and long, respectively. Color of pileus was also changes to whitish grown under high temperature. Physical structure shown as hardness and gumminess of stipes grown at high temperature, fruit body were soften than that of low temperature. Microstructures of fruit body grown at high temperature shown fast-discharge of basidiospore and sytoms aging. vacuolation in the cell observed at mycelium grown under high temperature. Optimum temperature for vegetative growth of fruit bodies were $15^{circ}C$, and shown regular arrangement of mycelium on the surface of stipes.