Abstract: Drilling in coal seam （DCS） is an important aspect of geological work in coal mining.As the development of mining technology for coal,now,in many countries,not only horizontal exploration holes of more than 1500 meters in depth and big engineering holes of 200～600 meters in depth can be drilled,but also the direction of drilling can be efficiently controlled by using stabilizer apparatus or Dyna-drill.In China the study of DCS has just begun.We think that in the coming five years,the equipments,technology and instruments of DCS will be developed.