The present invention relates to the technical field of railroad passenger car, and more particularly relates to a sleeper compartment of a railroad passenger car. The sleeper compartment may be an open type or a private booth type, comprising: sidewalls, partition walls, and two columns of longitudinally arranged sleepers that are parallel with each other; each column of the longitudinally arranged sleepers is formed by no less than two sleepers that are joined together, the sleepers comprise an upper-sleeper layer and a lower-sleeper layer; one partition wall is provided between adjacent sleepers; the length direction of the longitudinally arranged sleepers is consistent with the length direction of the railroad passenger car; the longitudinally arranged sleepers at two sides are fixed to the sidewalls respectively, and a corridor is provided between two adjacent columns of longitudinally arranged sleepers. The weight of the sleeper compartment of a railroad passenger car in this structure is evenly distributed, and passengers have better comfort when traveling.