Grain water relations were closely correlated with matter accumulation during grain development. In this study, QTL mapping for Grain Water Content (GWC) at four stages after pollination and Grain Dehydration Rate (GDR) during six intervals were done using 258 Recombinant Inbred Lines (RIL). Meta-QTL (mQTL) was revealed by meta-analysis using Bio Mercator for both traits herein and together with seven traits related with grain matter accumulation in our previous research. Among 40 QTL detected for GWC and 35 QTL for GDR, 45 QTL were stage/period specific. QTL on chromosome 5 could be considered as full-stage QTL. Eight of 11 mQTL included QTL for both traits. Grain matter traits were positively correlated with GWC, but negatively correlated with GDR in most cases. Low coincidences in QTL position and opposite allelic effects for two kinds of traits suggested that their simultaneous improvement might be realized. Selection for low grain moisture could be focused on QTL at bins 1.07- 1.08, 2.08, 4.03-4.04 and 5.03-5.04, while it should be followed to QTL at bins 7.02-7.03, 1.03-1.04 and 10.05-10.06 for high grain weight. However, this should be proved through practical selection, and the related marker intervals needed to be narrowed down in further research.