Disclosed is a method of encoding a video, the method including: splitting a current picture into at least one maximum coding unit; determining a coded depth to output a final encoding result according to at least one split region obtained by splitting a region of the maximum coding unit according to depths, by encoding the at least one split region, based on a depth that deepens in proportion to the number of times the region of the maximum coding unit is split; and outputting image data constituting the final encoding result according to the at least one split region, and encoding information about the coded depth and a prediction mode, according to the at least one maximum coding unit.