[en] The PROF-DD code system has been developed to generate the multi-group double-differential form cross section (DDX) library by processing the nuclear data file compiled with the ENDF/B-IV or -V format. This system consists of five steps : MCFILEF, RESENDD, SPINPTF, PROF-DDX and DDXLIBMK. By using this system, a user can easily produce a multi-group DDX library with a few input data, and make figures of the processed DDX data. The produced DDX library can be used for fusion neutronic calculations by the Monte Carlo code MORSE-DD, 1- and 2-dimensional Sn transport codes ANISN-DD and DOT-DD. This report has been prepared as a user manual of the PROF-DD code system. (author)