At this time very hard material machining and complicated shapes are needed, therefore non-conventional machining is developed to overcome these problems. Previous research has not been much discussed about making microchanel machining from aluminum. This study aims to analyze the influence of machining parameters with variations of electrolyte and stress concentrations in electrochemical machining (ECM) processes using unbranded brass electrodes against MRR and overcut values in aluminum microchanel. Aluminum plate cut into size 60x40x0,4 mm, then in-masking with microchanel pattern. For the machining process, the specimen is placed in a container tub and placed perpendicular to the brass tool with a 0.5 mm gap. Machining is done with variation of 7, 10 and 13 volt voltage parameters and variation of electrolyte concentration 10%, 15% and 20% with flowrate 6 LPM and machining time 270 seconds. After obtaining the results of microchanel machining, we recorded the specimen weight data before and after the machining that will be used to calculate the MRR and photograph the specimens to calculate the overcut value using the J-image application. The result of Microchanel machining show that the greater the electrolyte and voltage concentration used in the machining process the greater the MRR value. The highest MRR value is 2,7163 x 10-3 gr / dt at 20% electrolyte concentration and with a voltage of 13 volts. Electrolyte and stress concentrations greatly affect the value of each section overcut on the workpiece obtained. The best machining result is shown on machining with electrolyte concentration of 15% and with 7 volt voltage.