Malvaaegyptiaca L.(Malvaceae), a spontaneous plant used as a traditional medicine in Ghardaïa (SeptentrionalSahara Algerian). This paper reports the extraction and partial characterization of water-soluble polysaccharides from M. aegyptiaca leaves. These polysaccharides were obtained by elimination of the ethanol extract and sequential extraction in distilled water, followed by precipitation in 75% ethanol. The yield of extract is 1.46%(w/w). The crude water soluble polysaccharide extracts were further characterized and revealed the average values 17.14±1.43% proteins and 78.18±2.04% carbohydrates, among them 30.68±0.42% are uronic acid and47. 49±1.62% are neutralmonosaccharides. The acid hydrolysis was studied with trifluoroacetic acid (TFA) at two concentrations, with five durations of hydrolysis and at two temperatures. A single hydrolytic step with 4M TFA at 80 C for 4 h is suggested to be more effective in releasing monomers frompolysaccharides than other hydrolysis procedures. The identification of monosaccharide composition by high performance anion exchange chromatography with pulsed amperometric detection (HPAEC-PAD) methods shows 56.86% of galactose, 8.46% of rhamnose, 9.04% of arabinose, 5.05% of mannose and 20.57% of glucuronic acid.