Regenerated cellulose fibers are one of the most preferred fibers due to the comfort properties and friendliness features to the environment. Especially lyocell fibers among the regenerated cellulose fibers become more important because of the good handle properties. However, the appearance of the lyocell products is detonated during the usage due to the high fibrillation characteristic of the fiber. In order to prevent this, non-fibrillated lyocell fibers are developed by forming cross links in the structure. In this study, the relation between the physical properties and inner structures of the ordinary lyocell fiber and non-fibrillated lyocell fiber in 3.3 dtex fiber fineness were investigated., For this purpose, some physical properties and inner-structures of the fibers were examined and the relation between the difference of the physical properties and inner structures were tried to be found. The fiber strength properties were measured by using lnstron 1122 tensile strength tester, the microscopic views of the fibers were determined via optical microscope and scanning electron microscope; the inner structures of the fibers were defined by both Fourier Transform Infra-Red (FTIR) spectroscope and wide angle X-ray diffraction methods.