5-(p-Methylthio-o-methyl-pyrimidinyl)-2,4- pentadiyn-1-ol was synthesized by asymmetric couple method of Cadiot-Chodkiewicz and the mechanism of reaction was described. Several PDA's derivatives were obtained in good yields. These diacetylene monomers could easily dissolve in common organic solvents, and be polymerized thermally or under light illumination. Micro-and macroscopic third-order susceptibilities were measured by DFWM method for the yielded polymer.