Sodium carboxymethyl cellulose (CMC) and soybean soluble polysaccharide (SSPS) are negatively charged polysaccharides that are used to prevent casein aggregation in acidified skimmed milk drinks (ASMDs). The objective of this study was to examine the effect of CMC and SSPS combination on the stability of acidified skimmed milk drinks in comparison to their individual effects. Stability was evaluated based on the changes in sedimentation ratio, viscosity, zeta potential, and particle size distribution of casein micelles. Increased CMC or SSPS concentration resulted in decreased sedimentation ratio and size diameter, while viscosity and zeta potential increased. The use of CMC-SSPS blend at the ratio of 1:3 showed better stability of ASMDs compared to when the two stabilizers were used individually. Sedimentation ratio and size diameter obtained from the ratio of 1:3 (CMC-SSPS) had no clear significant difference (P<0.05) with those stabilized by the ratio of 0:4, but CMC was crucial in controlling the blend viscosity and zeta potential, hence improving stability. Furthermore, SSPS showed a better stabilization behavior than CMC when they are used alone. It can therefore be suggested that a combination of CMC-SSPS is more effective than the individual use of the two stabilizers in stabilizing ASMDs, and thus, CMC can effectively supplement SSPS in the production of stable ASMDs.