A pulse generator of an ultra wideband (UWB) system includes: a plurality of delay cells for receiving pulses, delaying the received pulses for a predetermined time, and outputting the delayed pulses; and an edge combiner connected to output ends of the plurality of delay cells for receiving the delayed pulses from the plurality of delay cells, outputting fine pulses corresponding to the delayed time, and generating one impulse signal with the outputted fine pulses. The edge combiner includes a plurality of XOR gates for receiving a first delayed pulse and a second delayed pulse from an nth delay cell and an (n+1)th delay cell among the plurality of delay cells and generating fine pulses, respectively, and an OR gate for receiving a first fine pulse and a second fine pulse respectively output from a first XOR gate and a second XOR gate included in the plurality of XOR gates.