Based on the fixed time observation data from 22 basic meteorological stations in Shandong, the daily atmospheric self-purification capacity index (ASPC) from 1961 to 2017 is calculated using A value method, climatic spatial-temporal characteristics are analyzed, and the ASPC mutation test is conducted using Mann-Kendall (MK) mutation test and Moving-t (MT) technique. The results show that the average ASPC presents significant downtrend (P<0.01) and its climate tendency rate is -2.61×104 km2·a-1. The ASPC downtrend in Shandong is remarkable (P<0.01) except in Zhangqiu and Weihai. The monthly ASPC is higher in each month of spring, but with time passing by, it obviously decreases over the years. The annual and seasonal spatial distribution of ASPC is relatively consistent, and it is higher in Shandong Peninsula and lower in inland areas such as the south of Shandong. The annual abrupt change of ASPC appears in 2003, and years of abrupt change of ASPC in spring, summer, autumn, and winter are respectively 2006, 2003, 2003, and 2005. The average ASPC in Jinan and Qingdao has shown significant downtrend (P<0.01) respectively since 1999 and 1993. Annual change of days of low ASPC is roughly opposite to the change of ASPC. Monthly ASPC involves obvious change in Jinan and Qingdao over the years.