Introduction: Maternal exposure during pregnancy can shape offspring immune programming and allergy susceptibility . This study used baicalin, a component of commonly used Chinese herbal medicines, to investigate its effects on offspring immunity . Baicalin was selected because it is widely used in China, has potential allergenicity , and serves as a model formaternal herbal exposure affecting offspring allergic risk. Objective: To evaluate how maternal baicalin exposure, with or without post-exposure challenge, affects offspring immune balance, allergen-specific antibodies, airway inflammation, and early allergic risk. Methods: BALB/c dams were assigned to control, exposure (BA-BSA 3.6% on gestational days 1, 3, 5), or exposure+challenge (same exposure plus BG-OVA on day 17). Offspring received ageappropriate OVA immunizations. Outcomes included serum allergen-specific antibodies,Th1/Th2/Treg balance, pulmonary transcription factors (GATA-3, T-bet, ROR t, FoxP3), and airway hyperresponsiveness (AHR). Results: Maternal exposure reduced early offspring baicalin-specific antibodies (BG-IgG 9648±3277 , BG-IgG1 5282±2166), whereas exposure+challenge increased them (BG-IgG 281700±74120, BG-IgG1 214700±76150, P