Abstract: In the present paper the mechanical alloying process of ZrO₂-50mol%CaO ceramics powderhas been investigated. It has been found that the high energy ball milling can.greatly enhance the reaction speed of ZrO₂ and CaO. The compound CaZrO₃ has been formed by 120h milling. The alloyingmechanism of brittle ceramics has been discussed and the Compound powder formed by milling wasconsidered playing an important role in the process.