Asthma is a heterogeneous disease characterized by chronic airway inflammation. Eosinophilic asthma is the most common subtype based on airway inflammatory classification. As alternative biomarkers for induced sputum，blood eosinophil，fractional exhaled nitric oxide，and serum periostin have been widely used in the study of eosinophilic asthma，but their ability to predict eosinophilic airway inflammation is controversial. Combined use of two or more biomarkers may improve the accuracy of diagnosis. In addition，with the development of omics technology and the in-depth understanding of the pathogenesis of asthma，new biomarkers are expected to be applied in clinic in the future.