In cutting of Ti-Alloys with extremely low thermal conductivity, the tool tip temperature rises significantly. Therefore, in high-speed cutting of Ti-Alloys, tool cooling using heat transfer by high pressure supply of water-soluble cutting fluid is carried out, but the cooling effect is small with respect to the supply amount. Therefore, in this research, we tried to suppress the heat generation during machining by utilizing the lubricating effect of the oil. In this test, high-speed milling with a very short cutting time realizes high-speed cutting of Ti-Alloys while securing the lubricating effect. And we confirmed the effectiveness of the lubricant by examining tool wear and cutting forces. In addition to the comparison based on the presence or absence of the lubricating oil, the comparison was also made based on the viscosity of the lubricating oil. As a result, when lubricating oil was used, it was confirmed that chipping and adhesion at the cutting edge were suppressed and the thrust force was also reduced. In addition, using a low viscosity oil agent maintained a better blade edge condition, suggested that a low viscosity oil agent with higher permeability exhibits more lubricating effect.