The effects of pyrolysis conditions on the pore structure of chars were studied for Dong Won an-thracite, Australia Coalex(HD) bituminous coal, Victoria subbituminous coal and Pakistan Lakla lignite. Sample chars were prepared under the condition of final pyrolysis temperatures of 800, 925, 1000℃, and pyrolysis heating rates of 2, 10, 30, 100℃/min and 900℃ isothermal(about 6000℃/min). Micropore surface area, micropore volume distribution, mean pore diameter, and macropore volume and macropore surface area of chars were measured. Pore volume of chars was affected by macropore of chars, and pore surface area was largely affected by micropore of chars. The pore surface area and the pore volume of char were increased at the higher final pyrolysis temperature, the higher pyrolysis heating rates and lower the rank of coals.