Objective To analyze the discrepancies in serum protein fingerprint between glucocorticoid (GC)-sensitive and GC-resistant individuals with primary immune thrombocytopenia (ITP). Methods After a 4-week GC treatment, patients with ITP were dived into the two groups. 32 patients were assigned to the GC-sensitive group, and 28 patients were assigned to the GC-resistant group. Clinical parameters were compared between the two groups, the protein expression patterns from all specimens were determined using matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MADLI-TOF-MS).Results The detection of Clinprot system and the analysis of CliprotoolsTM2.2 software shew that about 41 protein peaks were detected within the range of 700 Da and 10000 Da of molecular weight in the protein spectrum of serum specimen from 32 GC-sensitive patients and 28 GC-resistance patients, but there aren’t statistically differential(P＞0.05). Five proteins with molecular weights of 9289.84, 4644.96, 6666.94, 4964.12, and 7764.95 Da were differentially expressed after GC treatment in GC-sensitive group. And there aren't statistically differential after GC treatment in GC-resistance group. Conclusion We found five proteins in GC-sensitive group. These differential proteins may be closely related to the pathogenesis of ITP and the effect of the GC treatment.