A liquid crystalline polyester resin composition comprising 100 parts by weight of a liquid crystalline polyester; 50 to 150 parts by weight of at least one whisker selected from aluminum borate whisker and titanium oxide whisker; and 1 to 30 parts by weight of carbon black having a specific surface area of at least 200 m2/g. This liquid crystalline polyester resin composition has excellent mechanical properties and provides an insulator which is hardly charged.