Abstract: Under the conditions of pH≥11,atmospheric,and 95 ℃,calcium borate and sodium metaborate were prepared from borax,calcium oxide,and water.Calcium chloride was added to system after the reaction.Then,sodium metaborate can be transformed into calcium borate.After mixed solution displaced for 17 h in condition of 19~22 ℃,massive calcium metaborate crystals were prepared.Amountofsubstance ratio of borax,calcium oxide,calcium chloride,and water,the best time of reaction and the optimum placement temperature of mixed solution were investigated,respectively.Then analysis was carried out by FT-IR,TG-DTA,and XRD.Results showed that borax was totally utilized,excess calcium chloride can be easily removed from product,and purity of calcium borate crystal was more than 98%,and synthesic speed of crystal was improved more than 10 times.<BR>