Abstract: For the issue of rectangle packing problem, traditional lowest horizontal line method might
generate certain empty blocks that were not used, which would cause unnecessary waste of material.
To solve the problem, heuristic estimate is introduced into search process to achieve rectangle filling
for the empty blocks and improve utilization. For optimization packing sequence of rectangles using
genetic algorithm, a new strategy of setting different genetic factors by stages of evolution process is
applied to improve algorithm performance. The two improved methods are combined in union to
solve the rectangle packing problem. The test data of packing show that the proposed algorithm can
effectively improve packing results and improve utilization of material.

Key words: rectangle packing, optimization algorithm, lowest horizontal line, genetic algorithm