The theory model of the indent experiment of the brittle material was established, its specific energy was analyzed, and the calculation expression of the total specific energy for a single grain was given. Experiment process and results were given. Ultra-high speed grinding experiment was done, and its results were obtained. After the results were analyzed, the conclusions were gained that brittle materials could produce ductile-regime grinding under ultra-high speed shock. The model of mechanism of chip-formation due to shock in quasi-fluid phase on super-high speed grinding was established, and the chip formation hypothesis for the chip formation mechanism on ultra high speed grinding was produced.