This paper investigated experimentally effects of the temperature-dependent property on the laminar flow characteristics in the micro-channel, where water was used as a working fluid. A rectangular straight micro-channel was fabricated with the dimension of 57 μm (H) × 200 μm (W) × 48050 μm (L), in which the resistance temperature detectors (RTDs) were integrated to measure precise temperatures of the fluid directly on the inside-surface of the channel wall. A micro-heater was also installed at the outlet of the channel to generate the heat flux. We measured pressure drop by increasing mass flow rate and the applied heating power. At the same time, micro-Particle Image Velocimetry (micro-PIV) measured the detailed velocity fields along the microcharmel, where the wall temperature varied. Based on the pressure drop and Micro-PIV measurement, it was determined that the variation of the fluid property along the microchannel has an effect significantly on flow resistance but not considerably on the velocity profile. Also, it was observed that flow resistance and velocity field shows a good agreement with those estimated in the macro laminar theory under our experimental conditions.