Sustained release tablet is solid dosage form which is designed to release drugs slowly in the body. This research was intended to prepare and characterize the cross-linked excipients of co-processed xanthan gum-acacia gum (CL-Co-XGGA) as matrices for sustained release tablets with gliclazide as a model drug. CL-Co-XGGA excipients were cross-linked materials of co-processed excipients of xanthan gum-acacia gum (Co-XGGA) using sodium trimetaphosphate. Co-processed excipients of xanthan gum-acacia gum were prepared in the ratio of each excipient 1:2, 1:1 and 2:1. Co-XGGA and CL-Co-XGGA excipients were characterized physically, chemically and functionally. Then, the sustained release (SR) tablets were formulated by wet granulation method using CL-Co-XGGA excipients as matrices. Also, the dissolution study of the gliclazide SR tablets was carried out in phosphate buffer medium pH 7,4 containing sodium lauryl sulphate 0.2% for 12 hours. The results showed that the degree of substitution (DS) of CL-Co-XGGA 1:2, 1:1, 2:1 excipients were respectively 0.067, 0.082 and 0.08. Besides that, the excipients gel strengths were 14.03, 17.27 and 20,70 gF, respectively. The cross-linked excipients had improved flow properties and swelling capability compared to the Co-XGGA excipients. The results of the gliclazide SR tablets evaluations showed that all tablets were passed all tablet requirements. Moreover, the gliclazide release from SR tablets F1 - F6 revealed the sustained release profile, which was following zero order kinetics (F1, F2, F3, F6) and Higuchi kinetics (F4 and F5). It could be concluded that the obtained CL-Co-XGGA excipients might be used as matrices for sustained release tablets and could retard drug release up to 8 until 32 hours.