Calculations of the temperature coefficients of the elastic surface wave velocity and delay time were performed for the propagation along the X axis of rotated Y cut plane of the LiNbO3 and LiTaO3. Measurements of the temperature dependence of delay time of the elastic surface wave were also performed for the propagation along the X axis of a 130" rotated Y cut plane of the LiNb03 at the temperature range from liquid He to room temperature. Experimental value 70$ imes$10-6/$^{circ}C$ of the temperature coefficient of the delay time of the elastic surface wave agrees well with the calculated value 72.7$ imes$10-a/$^{circ}C$. The temperature coefficient of delay time of elastic surface wave propagating along the X axis of a 130$^{circ}$ rotated Y cut plane o( the LiNbO3 is approximately 16$ imes$10-6/$^{circ}C$ at the near temperature of liquid He.d He.