Effects of l-lysine on physicochemical properties of pork sausage were investigated. WHC values significantly increased using 0.8% l-lysine, but significantly decreased at 0.4% l-lysine (p<0.05), compared with controls. l-Lysine increased pH values and a* values, but significantly decreased CL, cohesiveness, L* values, and b* values (p<0.05), compared with controls. Addition of 0.4% l-lysine significantly (p<0.05) increased hardness, springiness, and chewiness values, compared with controls. SEM analysis showed that addition of 0.8% l-lysine induced formation of a smoother, more compact, and more uniform gel matrix, compared with controls. DSC analysis indicated that addition of 0.8% l-lysine significantly (p<0.05) increased thermal transition temperatures and enthalphy values, compared with controls, showing that interactions between l-lysine and myofibrillar proteins affected the properties of pork sausages.