In Minimum Quantity Lubrication machining, cutting fluid is provided as mist. Mist with different velocity and diameter may lead to different cooling, lubrication effect and cutting quality. Thus, cutting quality is highly influenced by spray characteristics in MQL machining. In this study, the mathematics model of mist flow was set up first. Then spray characteristics were tested by a 3-Dimensional Particle Dynamic Analyzer. In order to study the influence of spray characteristics on cutting quality, precision turning of 45 steel was performed by a CNC Super Precision Machine Tool. The results indicate that the lowest surface roughness was obtained by supplying more cutting fluid at proper position for spraying distance of 20mm.