Background: Acrylic resin is often used in dentistry as the basis of a denture. The type of acrylic resin that frequently used for a denture is heat cured acrylic resin. This one is choosen because it is quite cheap, its color is similar with the gingiva and it is stable in the mouth. However, heat cured acrylic is easily fractured. The basis of a denture should have high modulus electricity to make sure there will not be permanent deformation during chewing process. In this case, with the percentage raise of chitosan, it can be used to increase the tensile strength and young modulus. The meaning of chitosan itself is deacetylation of chitin that can be obtained from the shell of crab, shrimp and insect. Objective: The purpose of this research is to find out the influence of chitosan concentrate in acryic resin towards modulus elasticity. Research Method: The research method that is used is experimental laboratory with 16 samples and with each size 64mm x 10mm x 2.5mm. The samples are tested using UTM, while the data is analyzed using one way anova. Result: From 16 samples which are tested, the researcher obtained average results acrylic resin as the controler is 13.280, acrylic resin with concentration 0.13% is 15.772, with concentration 0.26% is 18.582, and with concentration 0.4% is 20.979. The analysis test result using one way anova is obtaining 0.192 value of p (p > 0.05) Conclusion: The conclusion is there is no influence of chitosan concentrate that is given to acrylic resin, so it does not caused any increase of modulus elacticity.