Allergen-specific immunotherapy (AIT) has confirmed its efficacy in improving the symptoms of allergic rhinitis. However, no reliable biomarkers have been identified to predict the efficacy of AIT were found. We aimed to find clinical and immunological markers to predict efficacy in children after 2 years of sublingual immunotherapy (SLIT). A total of 285 children diagnosed with allergic rhinitis were recruited. The clinical efficacy was evaluated by comparing endpoint and baseline symptom and medication scores (SMS). Baseline clinical and immunological markers (serum total and specific immunoglobulin [Ig]E) and their correlation with clinical efficacy were analyzed. Of the 285 children recruited, 249 completed the 2-year SLIT program. After 2 years of SLIT, 68.3% of the children showed a significant response. Children in the Remarkable Response Group had the highest baseline SMS and most extended disease duration, followed by the Effective Relief and Unresponsive Group. Correlation analysis demonstrated that SMS improvement was positively correlated with baseline SMS (r=0.67) and disease duration (r=0.35). SMS improvement was not correlated with age, body mass index, total or specific IgE levels, or their ratios. Our results show that baseline SMS and disease duration can predict the efficacy of SLIT. Our study can guide the selection of suitable candidates for SLIT.