Gold nanoparticles (AuNPs) was prepared via simple and green method by using polysaccharides as reducing and stabilizing agents at the same time. Hiren we used carboxymethylchitosan (CMCS) as a reducing agent for gold nanoparticle as well as capping agent. CMCS prepared based on our previous method by reacting chitosan with monochloroacetic acid in alkaline medium. AuNPs were prepared by using different concentrations of carboxymethylchitosan (0.2% w/v, 0.5% w/v and 1% w/v) at 100 oC for 1 hour. CMCS was characterized by using nitrogen content, carboxyl content and FTIR spectra. AuNPswas characterized by using UV spectrophotometry and TEM images. Finally, the cytotoxicity of the prepared AuNPs were evaluated using cell viability assay from MMT and IC50 values compared with AuNPs prepared by chemical methods. The results shows that AuNPs have normal distributed with 15-25 nm particle size and its cytotoxicity was lowered when prepared by this green method and can use GNPs safely in contact medical treatment with skin.