There is provided a novel pest control agent, particularly an insecticide or miticide. A substituted isoxazoline compound of General Formula (1): where A 1 , A 2 and A 3 independently are CH or N, etc., X 1 , X 2 and X 3 are independently are H, a halogen atom, etc., Y 1 is H, etc., R 1 is -C(O)R 1a , -C(S)R 1a , R 1a is -C(R 9 )(R 9a )-S(O) r R 10 , -C(R 9 )(R 9a )-S(O) t (R 10 )=NR 11 , etc., R 2 is H, etc., R 3 is CF 3 , CClF 2 , etc., R 4 is H, etc., R 9 is H, etc., R 9a is H, etc., R 10 is C 1-2 alkyl, etc., R 11 is H, etc., r is an integer of 0-2, t is an integer of 0 or 1; and a pest control agent comprising the compound or the salt thereof.