Abstract: The steel-concrete composite slim beam has a promising application prospect in multi-storey steel building because of its advantages such as low structural height, efficient fire resistance and good serviceability, etc. In this paper, the research on the composite slim beam was not only reviewed, but also the rigidity, load bearing capacity, effective width and bond of both laminated composite slim beam and deep deck composite slim beam were investigated through theoretical method, FEM and experimental method. Engineering application of the composite slim beam in some project was introduced as well. Finally, the research trend pertinent to the composite slim beams is previewed.