Pd(0) nanocomposites with the use of polycaprolactam (PCL) as reducing and nanostabilizing matrix have been developed and synthesized. The data about the mechanism of formation of nanoparticles in PCL matrix in conditions changing values of pH of the medium and ratio of concentration of the reagents have been obtained. Complexing nature of interaction of Pd(II) with PCL in the sour medium have been found out. The process of reduction of Pd(II) and formation of Pd(0) occurs at pH 9–10.5 and temperature 70–800C. The received nanocomposites can be recommended for creation of heterogeneous catalysts of synthesis for a number of organic substances.