Inclusion Criteria:  Aged 3-8 years old Healthy subjects judged from medical history and clinical examination Subjects themselves or their guardians able to understand and sign the informed consent Subjects themselves or their guardians can and will comply with the requirements of the protocol Subjects have received ≥2 doses of trivalent or quadrivalent infuenza vaccine before enrollment (Doses need not have been received during same or consecutive seasons); Subjects have not received infuenza vaccine before enrollment Subjects with temperature <=37.0°C on axillary setting  Exclusion Criteria:  Subject who has a medical or family history of any of the following: allergic history, seizure, epilepsy, brain or mental disease Subject who is allergic to any ingredient of the vaccine Subject with damaged or low immune function which has already been known Subject with acute febrile illness or infectious disease Major congenital defects or serious chronic illness, including perinatal brain damage Thrombocytopenia, blood coagulation disorder or bleeding difficulties with intramuscular injection Subject who has serious allergic history Subject who developed guillain-Barre syndrome post influenza vaccination Any prior administration of immunodepressant or corticosteroids in last 6 months Any prior administration of influenza vaccine in last 6 month Any prior administration of blood products in last 3 months Any prior administration of other research medicine/vaccine in last 30 days Any prior administration of any attenuated live vaccine in last 14 days Any prior administration of subunit or inactivated vaccines in last 7 days, such as pneumococcal vaccine Any medical, psychological, social or other condition judged by investigator, that may interfere subject's compliance with the protocol or signature on informed consent for subject's guardian