This work was designed to study the effect of carboxymethyl cellulose (CMC) as synthetic hydrocolloid agent and okra mucilage (OM) as a natural one on the rheological properties of rice bread (RB) compared with regular wheat bread (WB). The water activity (a_w) of the prepared bread samples was also determined. Therefore, texture profile analysis (TPA) was employed using CT3 Texture Analyzer and Decagon Aqualab Meter Series 3TE for a_w. The results revealed cohesiveness, resilience, and springiness of fresh WB (T1) are higher than those of RB (T2), which are decreased by extending the storage period. On the other hand, the hardness, chewiness, and gumminess of fresh WB (T1) are lower than those of RB (T2). These characteristics are generally decreased in the fresh RB by increasing the ratio of added hydro-colloidal agents (CMC or OM). The best results were obtained by the addition of 2.0g CMC (T6) or 3.0g OM/100g (T14) to the RB formula. The water activity a_w of the fresh WB (T1) is 0.898 which gradually decreased reaching to 0.884 with no significant difference. The same trend was also observed for RB (T2). On the opposite as the hydrocolloid agent increased in the RB formulation the a_w gradually increased till reaching 2.5-3.0 g hydrocolloid/100g rice flour (RF) in the bread formula.