Laminate floor coverings, with fiberboard in the middle layer, are hygroscopic which caused potential dimension instability. The paper tested thickness swelling (TS) and water absorption (WA) of 10 commercial laminate floors (LF) according to G/T 18102-2007 (GB/T) and LY/T 1611-2011(LY/T) and analyzed correlation between them. The results show that TS obtained by the GB/T method differed significantly from LY/T methods at the initial 14 days. 7d-TS and 7d-WA values of test specimen measuring 50 by 50mm both correlated well with internal bond (IB). For both kinds of test methods, the moisture content almost reached saturation at 28 days.