The purpose of this study is to compare the difference of the temperature and the specific heat capacity. A sheet of insulation made from Hevea Brasiliensis tree leaves by using 100 watt bulb is a heat source, and the thermocouple is a set temperature was studied. Insulation Hevea Brasiliensis leaves thickness, 3.0 cm. Can the heat better insulation Hevea Brasiliensis leaves thickness, 1.0 cm and 2.0 cm. It can be seen from the difference of the temperature of the light to the south side sheet of insulation. A difference of temperature of 14.0 15.1 16.5 respectively, when calculating the heat resistance, it was found that the insulation sheet Hevea Brasiliensis leaves thickness, and 1.0 2.0 3.0 cm. The heat resistance and is 1.26103 1.35869 1.38632 square metre Kelvin per watt, respectively, and the specific heat capacity is 0.02381 0.01827 0.01225 joules per kilogram and Kelvin. However, the specific heat capacity of heat accumulation in the body. The heat passed down under the sheet insulation is less or pass slowly. The south side sheet insulation temperature less than the temperature light. Then try using the sun as a heat source, the results with Xplorer GLX PS - 2002 is time 48 hours. During the daytime, 6: 00 - 18: 00 clock, temperature in the South sheet of insulation have lower temperature outside. While night temperature under temperature higher than the temperature insulating plate outside. Because the factors caused by wind and moisture. Result the temperature outside is constantly changing.