Agglomerated grains of diamond bonded with Cu-P alloy powder are prepared at various sintered temperatures. Differential thermal analysis（DTA） and X-ray diffraction（XRD） are used to test the melting characteristics and phase composition of the Cu-P alloy. A scanning electron microscope（SEM） is used to analyze the microstructure of the agglomerated grains of diamond, the wettability of diamond and the bond interface. The physical properties such as single particle compressive strength, impact toughness（TI），porosity and average pore size of the agglomerated grains of diamond are tested. Meanwhile, the grinding performance of the agglomerated grains of diamond prepared at various sintering temperatures is compared, and their grinding mechanism is explained. The results indicate that for agglomerated grains of the diamond sintered at 760 ℃，the diamond is well wrapped by Cu-P bond with a good wettability and an appropriate protrusion height. The agglomerated grains of diamond have excellent mechanical properties. Its single particle compressive strength，impact toughness, porosity and average pore size are 23 N，78%，29.33% and 18.53 μm，respectively. The agglomerated grains of the diamond sintered at 760 ℃ show the best grinding performance. After grinding, the agglomerated grains of diamond in the grinding wheel are in a semi-wear state. Moreover，the grinding ratio to zirconia ceramics is 24.8，and the surface roughness is 1.01 μm.