Leucite is the potassium-aluminum-silicate (K2O,.AI2O3, 4SiO2) with high thermal expansion coefficient. That is a very important component of felspathic dental porcelain, especially for ceramicfused-to-metal restorations. This paper demonstrated the method to create the composites by mixing powder of synthetic leucite with dental felspathic porcelain Do (rates of leucite P from 5 to 30 percent by weight) and sintering at 1000°C with a swell time of 30 min. Average thermal expan.sion coefficient of composites increased from 9.83 to (11.91-13.16) *10-6/K in accordance with application for dental porcelain of porcelain-metal system. Other properties of those composites such as bending strength, chemical durability, thermal shock resistance (refered to ISO 9693-1999) are increased. The highest bending strength (to 35.9 percent) is for samples containing 15-20 percent of leucite powder.