A halogen-free flame retardant polybutylene terephthalate resin composition contains 5 to 80 parts by weight of a phosphorus flame retardant (B) having a polyester structure in the main chain, 20 to 120 parts by weight of a nitrogen compound (C), 1 to 50 parts by weight of talc (D), and 0.1 to 2 parts by weight of an anti-dripping agent (E), based on 100 parts by weight of a polybutylene terephthalate resin (A) and exhibits a comparative tracking index of 400 V or higher in a tracking resistance test in accordance with IEC60112. The halogen-free flame retardant polybutylene terephthalate resin composition does not contain a halogen containing flame retardant, has high flame retardancy and high tracking resistance, and can be suitably used as members for electric/electronic parts.