In this paper,we study the current-voltage characteristics model o f the high power light emitting diode (LED) chip.Based on the particularity of the high power LED chip and the classical current-volta ge characteristic model of PN junction,we put forward a new model of current-voltage characteristics for hi gh power LED chip and its optimization model through theoretical derivation,analysis and selection of dif ferent basis functions.The coefficients of the two new models of current-voltage characteristics for high power LED are then estimated based on the least square method.Subsequently,we conduct comparative study on the actually measured current-voltage characteristic data of high power LED chip from three well-kno wn enterprises.The results show that the two new models out performthe classical current-voltage characteristic model of PN junction in accuracy with a large m argin.In particular,the experimental results from the optimization model are hi ghly consistent with the measured data from the three well-known enterprises.