Abstract: A flow-injection mass spectrometric metabolic fingerprinting method in combination with chemometrics was used to study the characterisation of daylily flowers from different drying processes. 30 daylily flower samples with three different drying treatments(vacuum freeze drying,solar drying and hot-air drying treatments)were extracted in a simple way and were directly injected into the mass spectrometer for the analyses with no column used. FIMS fingerprinting method required 2 min of analysis time per sample. Based on the intensities of the ions at m/z 100~1 000,principal components analysis and partial least square discrimination analysis were utilized to analyze by Simca-P software. The results showed that prominent ions at m/z 191.06,259.09,341.11,503.16,421.15,609.15,665.21,711.22,827.27 and 989.32.Daylily flower samples from different drying treatment were classified into three clusters in scores plot by PCA and PLS-DA analysis. The cumulative contribution rate was 91.2% in the PCA model,and the prediction accuracies of validation set were 91.2% in the PLS-DA model. The biomarkers which played the most important roles in classification were screened out. FIMS as a novel and characteristic fingerprinting method could be widely and efficiently used in characterisation research of agricultural products from different processes.