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Maximum yield of dextran was obtained when using ground date seeds. Different concentrations of date seeds were applied and the highest dextran production was achieved at 6 g/flask. Extraction of dextran was carried out using ethanol. The molecular weight of the purified dextran was 67 kDa by GPC. Spectral analysis showed that dextran contains D-glucose units in a linear chain with consecutive α-(1, 6) linkages. The melting temperature (Tm) was 70.56oC, and the value of ΔH was-290.57 mJ, as determined by DSC analysis. The TGA clearly showed the thermal stability of purified dextran. The analysis showed three stages of degradation process. An initial loss of about 0.577 mg (2.17%) weight occurred at 30-75 C, second loss of about 0.822 mg (3.1%) weight occurred at 75-125 C and the third loss of about 0.427 mg (1.61%) weight occurred at 125-175 C. Surface morphology of dextran using scanning electron microscopy showed dextran has a crystalline form which is attributed to the presence of hydroxyl groups which increase crystallinity of dextran, also, dextran showed a compact structure characterized by transversal arrangement which reflects brittleness of dextran and seems to have a porous structure. The cytotoxicity assays on human normal melanocytes (HFB 4) revealed no toxic effect. However, a clear decrease in cell survival was observed in case of human liver carcinoma (HEPG 2) and cervical carcinoma (HELA) tumor cell lines.