Newly discovered ManchurianLanguage historical archives show that the begi nning of Laoheishan volcanic eruption was on January 14,1720 A.D., while the e n d on March, 1721; and the volcanic eruption lasted for one year and two m onths. The beginning of Huoshaoshan volcanic eruption was on April 26, 172 1, the end on June, 1721. Its activity lasted for about two m ouths. The volcanic lava flows blocked the Wudelin river, forming "th e Wudelin ponding", and named as "Wudalianchi" today. There are cl ose relations between earthquake activity and volcanic eruption in the volcanic region.