The stability of cellulose acetophthalate latex (Aquateric((TM))) was studied with differential scanning calorimetry, spectrophotometry, and scanning and transmission electron microscopy. We investigated the effects of pH, temperature and shaking on physicochemical properties of the latex particles. Stability of the polymer was most strongly affected by pH; hence, we conclude that the stability of this latex reaches a maximum at acid pH values, whereas stability is lost at neutral and alkaline pH.