The high cost of real-time kinematic (RTK) differential GPS units required for autonomous guidance has limited their use in practical auto-guided systems applicable to small-sized farming conditions.This study was conducted to develop an autonomous navigation algorithmfor row crop applications that could detect uncut crop edges in real-time using a laser scanner.The laser sensor was mounted on top of a crawler type motor-driven mobile platform to build the lines of uncut crop edge for path tracking based on the calculation of relative positions of row crops.The developed navigation algorithm was embedded on a field test platform consisting of a 23kW Korean tractor, an array of low-cost single GPS receivers, and a laptop computer.Field testswere performed in an agricultural field growing a row crop to investigate the effectiveness of using the laser scanner and low-cost single GPS receiver for autonomous path tracking.