BLDC motor electronically performs rectification without brushes. So, the BLDC motor has a high durability and reliability. However, the temperature rise in the motor is a cause to increase the resistance of the copper windings and decrease the performance of the permanent magnets. This study numerically analyzed the temperature distribution of 600 W air-cooled BLDC motor according to air flow rate. The inlet flow rate is changed to 5, 7.5, 10 LPM to predict the temperature of the copper windings and permanent magnets. To verify the reliability of the numerical simulation, the motor load test is carried out. The efficiency of the motor measured in the load test. The efficiency of the uncooled motor and the 10 LPM air-cooled motor is calculated as 85.2 % and 86.2 %, respectively. This study is expected to be used as a basic research that can be applied to optimization of direct cooling technology of BLDC motor.