[en] In this report we study parallelization for two First Principles molecular dynamics programs. One is a traditional First Principles molecular dynamics program, and the other is a real-space molecular dynamics program which attracts an attention recently because of its high speed. The target machine is NEC SX-4, with the parallelization method adopted for shared memory machines. It is shown that 3.7 times acceleration is achieved with 8 CPU parallelization for the traditional First Principles molecular dynamics program and 3.9 times acceleration with 8 CPU parallelization for the real-space molecular dynamics program. (author)