The structure, brittleness and dry sliding tribological characteristics of laser-cladded Al2O3 ceramic coatings on W18Cr4V steel have been studied by means of SEM, TEM, EDAX, sound emission and wear tests techniques etc. The results show that the Al2O3 coating cladded by laser consists of columnar grains of α-Al2O3 and a small amount of Ni2Al18O29 among Al2O3 grains. The hardness value of Al2O3 coatings cladded by laser is about 2351～2667Hv0.2. The britlleness of the laser-cladded Al2O3 coatings is increased to some extent than that of a plasma-sprayed Al2O3 coating. In dry sliding wear condition the wear resistance of the Al2O3 coatings is about 2 times that of the plasma-sprayed Al2O3 coating, and the laser-cladded Al2O3 coatings are worn by brittle peeling and abrasive wear.