The alkaline-chloride solution based pretreatment process is an attempt to get cellulose from sago pulp fiber. The two stages of pretreatment carried out were 500 mesh sago fiber soaking in 15% ammonium hydroxide solution and hydrolysis in 4% chloric acid at a temperature of 95oC. During the pretreatment process, lignin and hemicellulose compounds were released with a percentage of 35% and 74% respectively. The pretreatment stage physically causes discoloration of sago pulp fiber. The acquisition of sago pulp fiber cellulose was strengthened by the appearance of typical peaks on IR absorption at wave number 1429.4 cm-1, 1322.4 cm-1, 1157.3 cm-1, 1110 cm-1, and 897 cm-1. The results of Scanning Electron Microscopy show that the cellulose obtained has a porous, rough and fibrous surface with irregular length and irregular fiber location. In addition, cellulose has a single phase with a crystal size of 15 nm