This paper proposes a sawtooth-shape planar lightguide solar concentrator. In this design, sunlight is collected by each lens in a two-dimensional lens array and is coupled into the planar lightguide using localized micro structure placed at each lens focus. Where the micro structure is the dimpled structure [2010 International Optical Design Conference, paper ITuE5P]. In this design, one side of the planar lightguide was shaped in a sawtooth-form shape. The usage of the sawtooth-shape planar lightguide prevents most leakage of guiding rays after multiple reflections in lightguide. Simulation results show that the sawtooth-shape planar lightguide solar concentrator can achieve 92% optical efficiency at 300× concentration.