The committee on science of the Commission on the Reorganization of Secondary Education has carried on its work by means of discussions, correspondence, and formulation of preliminary reports for over seven years. The discussion of preliminary reports by groups, committees, and at meetings of science teachers has revealed progressive work already under way and has led to the trial of preliminary recommendations. Some of the improvements that the committee sought to effect have already been adopted by many of the best schools. The full report herein presented, formulated through this procedure, incorporates practices that have proved most useful. It asks for only those features of reorganization that have been found to work well, or which by fair amount of trial promise improvements. Further experiments with new courses in science, or with the readjustment of older courses, may make desirable and necessary a revision of the report before many years have passed. The report embodies contributions and criticisms of more than 50 science teachers and administrative officers. It does not include every proposal, as many such proposals are not fully approved by others. Some members of subcommittees have been unable to send criticisms of the full report, but because of their previous important work on subcommittees their names are included in the list of members. Appendix includes: The science teacher. (Contains 1 footnote.) [A Report of the Commission on the Reorganization of Secondary Education, appointed by the National Education Association. Best copy available has been provided.]