The objective of this thesis is to design and implement single-stage forward converter with power factor correction. Its advantage is to improve power factor and reduce input current harmonics. The power device for power factor correction and DC/DC conversion is merged for the single-stage forward converter and thereby reducing the number of power device and cost. The control IC is NCP1651 of ON Semiconductor. The specifications of the designed converter include 110 V/AC of input and 48 V/DC, 100W of output. Experimental results show that the designed and implemented converter works from no load to fully load. Moreover it is shown that its power factor higher than 95% and efficiency more than 80%. These results verify the theoretical analysis, design and implementation.