The demands of mechanical precision micro machining technology have increased due to the need for micro scale precision shapes and parts in biotechnology, optics, and machinery. In the micro-machining process, the machining parameters must be controlled in order to improve the precision and quality of machined parts. Improvements must be made in exclusive precision machining and extensive study of machining technology must be conducted in order to overcome current challenges in the micro machining process. This paper investigates the correlation between the machined surface condition and acoustic emission(AE) signals characterized according to the cutting conditions in the miro-machining process. Micro end mills (200 ㎛ diameter) and an air turbine spindle (120,000rpm) were used machine aluminum 6061-T6. The characteristics of the AE parameters were extracted in order to monitor the condition of the machined surface texture in micro milling process.