This study aims to: 1- Modify Iraqi natural waxes by adding some natural and chemical materials in order to produce new experimental modelling waxes that can be used in dentistry. 2- Evaluate the new waxes by measuring the physical properties according to ADA specification No. 24 and ISO 1561. 3- Evaluate the manipulation of the prepared experimental modelling waxes in constructing maxillary completely edentulous record base.The results showed that the addition of 20% Na-CMC, 20% gum Arabic, and 20% rosin to hard paraffin led to decrease the maximum melting point, flow, thermal expansion and dimensional changes but increase the minimum melting point and hardness of the hard paraffin. The starch is the same as other additives except that it leads to decrease the minimum melting point but increase the maximum melting point and the thermal expansion of hard paraffin. The rosin is the most effective one on the properties of hard paraffin than other additives. It was concluded that the experimental modelling waxes:(hard paraffin beeswax) and (beeswax+starch) have the most nearest properties to control and ADA specification than other waxes