This paper studies the relations between the great Wenchuan earthquake and the active-quiet periodic characteristics of strong earthquakes,the rhythmic feature of great earthquakes,and the grouped spatial distribution of MS8.0 earthquakes in Chinese mainland.We also studied the relation between the Wenchuan earthquake and the stepwise migration characteristics of MS≥7.0 earthquakes on the North-South seismic belt,the features of the energy releasing acceleration in the active crustal blocks related to the Wenchuan earthquake and the relation between the Wenchuan earthquake and the so called secondarc fault zone.The results can be summarized as follows:1 the occurrence of the Wenchuan earthquake was consistent with the active-quiet periodic characteristics of strong earthquakes;2 its occurrence is consistent with the features of grouped occurrence of MS8.0 earthquakes and follows the 25 years rhythm(each circulation experiences the same time) of great earthquakes;3 the Wenchuan MS8.0 earthquake follows the well known stepwise migration feature of strong earthquakes on the North-South seismic belt;4 the location where the Wenchuan MS8.0 earthquake took place has an obvious consistency with the temporal and spatial characteristic of grouped activity of MS≥7.0 strong earthquakes on the secondarc fault zone;5 the second-arc fault zone is not only the lower boundary for earthquakes with more than 30 km focal depth,but also looks like a lower boundary for deep substance movement;and 6 there are obvious seismic accelerations nearby the Qaidam and Qiangtang active crustal blocks(the northern and southern neighbors of the Bayan Har active block,respectively),which agrees with the GPS observation data. This paper studies the relations between the great Wenchuan earthquake and the active-quiet periodic characteristics of strong earthquakes, the rhythmic feature of great earthquakes, and the grouped space distribution of MS8.0 earthquakes in Chinese mainland.We also studied the relation between the Wenchuan earthquake and the stepwise migration characteristics of MS ≧ 7.0 earthquakes on the North-South seismic belt, the features of the energy releasing acceleration in the active crustal blocks related to the Wenchuan earthquake and the relation between the Wenchuan earthquake and the so called secondarc fault zone The results can be rounded as follows: 1 the occurrence of the Wenchuan earthquake was consistent with the active-quiet periodic characteristics of strong earthquakes; 2 its occurrence is consistent with the features of grouped occurrence of MS8.0 earthquakes and follows the 25 years rhythm (each time experiences the same time) of great earthquakes; 3 the Wenchuan MS8.0 earthquake follows the well known stepwise migration feature of strong earthquakes on the North-South seismic belt; 4 the location where the Wenchuan MS8.0 earthquake took place has an obvious consistency with the temporal and spatial characteristic of grouped activity of MS ≧ 7.0 strong earthquakes on the secondarc fault zone; 5 the second-arc fault zone is not only the lower boundary for earthquakes with more than 30 km focal depth, but also looks like a lower boundary for deep substance movement; and 6 there are obvious seismic accelerations nearby the Qaidam and Qiangtang active crustal blocks (the northern and southern neighbors of the Bayan Harmony block, respectively), which agrees with the GPS observation data.