The Beihuaiyang (on the northern margin of the Dabie Mts.) Mesozoic volcan ic and intrusive rock belt, which is from Xinyang of Henan Province in the west to Shuc heng of Anhui Province in the east, comprises early subintermediate and subalkaline pyroclastic rocks, lavas and intrusive counterparts and late aci dic volcanic rocks and intrusive counterparts. Former researchers have made many chronological studies but the methods they used were confined to the KAr meth o d for whole rocks and the 40Ar39Ar method for individul mi nerals. Here we system atically date the volcanic and intrusive rocks of the belt mainly by way of the Rb S r isochron method for whole rocks or wholerock and minerals as well as the   40Ar 39Ar method for individul minerals and the UPb dilute method f or single z ircon grains. The results show that the peak volcanic or intrusive activity was in the sp an of 130~140 Ma and the late acidic activity was around 117 Ma, both belong to the early Cretaceous.