To find out the dimensional stability factors of single bar warp knitted fabrics, CPC, WPC, and loop length were measured in a dry relaxed state and tumble relaxed state. Then, relaxation parameters called Kc, Kw, and Ks were calculated by the parameter equations for warp knitted fabrics in two different states, and comparative study of relaxation parameters in two different relaxation states were made. Also, we made an experiment in shrinkage of each state so that we found out the stage when the dimension was stabilized. Finally, the tendency of shrinkage by density and stitch were analyzed.