Fluid saturated with CO2 is common acid one. Carbonate mineral may be solved in the acid condition and secondary intergranular pores may be produced，which is the important origin of secondary pores. Experimental installation for diagenetic simulation was designed. Two ways of fast heating and slow heating were adopted with a temperature range from 50 ℃ to 120 ℃. Four water-rock experiments and one hydrothermal experiment were made to research the dissolution of calcite under different heating rates and the formation mechanism of the secondary pores of the carbonate. At the beginning and end of the experiments，all the calcites were weighed，and the dissolution topography of the calcite for observation were observed under the optical microscope and scanning electron microscope. It shows that dissolution rate of the calcite is fast and the dissolution was controlled by temperature and CO2 partial pressure（ pco2）. The fall of the temperature and rising of pco2 is beneficial to the dissolution of calcite. The faster the temperature rose，the more the calcite would be dissolved. In the sealed system，after the calcite was dissolved for quite a time，the dissolution of the calcite will be inhibited by the high concentration of ion. Along with the dissolution of the calcite，the dissolution topography of the calcite experienced 4 stages：dissolution micropore，dissolution belt，dissolution sawtooth and dissolution crystalline cone.