Abstract:Using the TEM technique we have studied the dislocation substructures of mantle-derived olivine from the alkali-basalts situated in two Cenozoic rifts, i. e. Klemonferant of the central massif in France and Wanquan of Hebei on the northern margin of Sino-Korean plate. Based on the analysis of dislocation type, diffractive pattern,diffractive vector g, Burgers vector b and dislocation slip system, we conclude that the deep-source olivine-bearing inclusions first underwent high一temperature(over 1000℃)creep stage in upper mantle characterized by subgrains, dislocation walls, dislocation ring,〔l00) screw and edge-free dislocation and disloration net as well as{okl}〔100) and(001) [100〕dislocation slip systerns of high temperature creep, Then as the deep-source inclusions moved from upper mantle to the crust,they experienced lowtemperature(lower than 600℃一800℃)strain manifested by long dislocation line and (110) [001] and(O10) [001] slip systems,The presence of new crystals suggests that they also suffered local rising of temperature later.