Plant cellulose differs from that ofbacterial's. Bactl:rialcellulose has greater fibre density than plant cellulose. When sodium hydroxide was added to cellulose, it enlarged the si2e ofpores, hence decreased the cellulose density. Sodium hydroxide treatment has been known to increas the yield for carboxymethylcellulose (CMC) made of those two celluloses. In this experiment, CMC was made from two types of cellulos( bycarboxymethylation using chloroacetic acid. The carboxymethylation was carried out by reacting 18 g of chloroacetic acid ,vith5.5 g cellulose in isopropanol media with NaOH concentration ranging from 30 to 40% at 55.C. Higher NaOH concentrat onsincreased the degree of substitution ofCMC and also lower the amount of water insoluble material. The 35% NaOH prodl cedbetter CMC product as compared to 30% concentration, and higher degree of substitution. Nevertheless, the bacterial cellu loseCMC had lower content of water insoluble material. The degree of polymerization in bacterial cellulose CMC was 142.5 whileit was only 121.4 for the plant cellulose. This study also showed that despite having denser fibre, the bacterial cellulose was nloreaccessible than that of plant cellulose when it was alkalized with NaOH 35%, which makes it easier to react with carboxymethylagent. However, the product was imferior as compared to the requirement for gum cellulose.Key words: Carboxymethyl cellulose, bacterial cellulose, plant cellulose. Ade Awalludin, Suminar Setiati Achmadil dan Novik Nurhidayat; Departemen Kimia, FMIP A -IPB; Laboratorium Biosisternatika, Puslit Biologi -LIPI