Background: There are many materials used in the making of artificial teeth. One of them is acrylic resin. The acrylic resin used in the field of dentistry is divided into several types, which are acrylic swapolymerization resin, polymerization light acrylic resin, and hot polymerization acrylic resin. Until now, RAPP is widely used as the material of making removable artificial teeth base because it has a number of advantages, some of them have quite satisfying aesthetic, good thermal conductivity, low water absorption, biocompatible, easily manipulated, and repaired without needing experts, and also economical. However, RAPP still have many disadvantages especially in strengths and hardness so that this material sometimes crack or break after some time of usage due to collision and the respectively pulling. This needs a good mechanic strength for the base of artificial teeth, one of them is transversal strength. Transversal strength is the resistance of a thing when receiving load at mastication time. The artificial teeth plate made of methyl methacrylate can be strengthen by the addition of reinforcing materials into the base of artificial teeth to increase transversal strengths and pressure acceptance. Chitosan, which is chitin derivative nature polymer compounds isolated from fishery wastes, such as shrimp shells and crab shells with chitin content between 65-70%. Research Purpose: This research aims to determine the effect of chitosan concentration in acrylic resin to transverse power. Research Method: The research method used is laboratory experimental with 16 samples with the size of 65mm x 10 mm x 2.5 mm. The sample is tested by using UTM tools. The data is analyzed by using One Way Anova test. Research Result: There are 16 samples that have been tested, the average result of acrylic resin as control is 53,130, acrylic resin with the concentration 0,13% is 47,9025, concentration 0,26% is 60,9750, and concentration 0,4% is 54,2775. The result of analysis test using One Way Anova got p value equal to 0,319 (p> 0,05). Conclusion: There is no chitosan concentration effect given in the acrylic resin so that it will not cause an increase in transverse strength.