To provide a nucleating agent for polyamide that has the higher crystallization kinetic and shows excellent mechanical properties as rigidity and heat-resistant stiffness.

The nucleating agent for polyamide resins is a metal salt of a monoterpene-diphenol prepared by addition of 2 molecules of a phenol to a 1 molecule of a monoterpene. In a preferred embodiment, the metal of the metal salts is selected from the group consisting of sodium salt, potassium salt and magnesium salt. The polyamide composition comprises 100 pts.wt. of polyamide and 0.001-20 pts.wt. of the nucleating agent.