Effect of soy protein isolate (SPI) (0.5 to 3%, w/w) on physical, chemical, sensory, and microstructure properties of light pork burgers containing added water incorporated with 0.7% mixed gum (konjac/gellan gum= 3:1) was carried out. Increasing of SPI levels resulted in significantly (p<0.05) higher cooking yield, lower reduction in diameter, and darker color of light pork burgers in relation to the control. Textural characteristics including cohesiveness, springiness, and chewiness significantly increased (p<0.05) with increasing of SPI up to 2% level; however, decreased these parameters were evident at 3% SPI used. Sensoryresults indicated that the 2% SPI light formulation showed significantly higher (p<0.05) scores for texture and juiciness than those of the control. The product was considered nutritious and provided the reduction of fat and total caloric content about 62.3 and 43.1% of the fullfat product, respectively.