Apatite forming and bonding ability of Ti based bulk metallic glass ((Ti0.40Zr0.10Cu0.36Pd0.14)99Ca1: BMG) were investigated as a new type of biomaterials. Powder mixture of CaHPO4･2H2O and Ca(OH)2 and the BMG disks were treated with autoclave for hydrothermal hot-pressing simultaneously (150°C, 40MPa). And then the BMG disks were soaked in simulated body fluid (SBF, Kokubo solution). Apatite were deposited and covered on the surface of the BMG. It was firstly demonstrated that surface of Ti based bulk metallic glass could be revealed apatite forming ability.