On the basis of Interlock, the application of bit, tuck and welt(interlock, royal interlock, mock royal interlock) was made by varying the density of the double hit fabrics and the mechanical properties of these fully relaxed fabrics were measured using KES-FB System. The analysis was carried out on several major characteristics in connection with density and such structures as loop configurations. The results were given as follows; 1. Interlock and Mock royal interlock stitches showed similar tendencies in bending, shear and tensile properties with the increase of MTF(Machine Tightness Factor). 2. Royal interlock gave relatively high values of bending rigidity and shear stiffless and big geometrical roughness in the direction of course. 3. The total hand value of double bitted fabrics was mainly affected by Stiffness rather than Smoothness, Sofuless and Fullness, and so the increase of MTF made the higher values of THV.