A large number of polymeric materials have been investigated for their large third-order nonlinear susceptibility. Here a series of new nonlinear optical polyyne-polymers containing Pd or Ni in the main chain are described. It is decovered that the metal polyynepolymers are showed to have large X(3) value (X(3) ≌ 3 X 10-13 esu, γ ≌ 5 X 10-31 esu) and low absorption in the visible and the near infrared regions, making them potentially useful in many applications according to the results of Degenerate Four-Wave mixing (DFWM).