Drawing processes and print processes for respective pages are performed in accordance with print commands by a plurality of processors. The print commands over the plurality of pages are stored in a command buffer. While successively allotting the drawing processes for different pages to different processors, a chain of the print commands ranging over the plurality of pages is fetched from the command buffer, and imaginary drawing operations for setting drawing attribute parameters of respective pages are executed sequentially without executing real drawing operation for printing actual drawings. The real drawing operations are executed for pages having completed the imaginary drawing operations by the allotted based in parallel on the print command chain and in accordance with the drawing attribute parameters set during in the imaginary operations.