Based on daily maximum temperatures in summer and minimum temperatures in winter respectively from 1961 to 2010 in Shandong province, skewed distribution characteristics and variation trend of extreme high and low temperatures have been analyzed by Box-Cox transformation. Results show that skewed indexes distributions of extreme high temperature in most areas obeys the rule of increasing from southeast to northwest, revealing that their left-partial levels relatively decline and the occurrence of abnormal high temperature in summer accordingly rises. Due to the effects of terrain and latitude, areas where skewed indexes distribution of extreme low temperature is left-partial are almost equal to right-partial areas. During the transition from the first climate state via the second one to the third one, skewed indexes of extreme high temperature in summer and extreme low temperature in winter in most areas of Shandong province are gradually going up, which indicates a more frequent occurrence of extreme high temperature in summer but a declining occurrence of extreme low temperature in winter.