The aim of the present study was to investigate the effect of non-protein components (AEVA-S), crude protein hydrolysates and their fractions from aqueous extract from velvet antler (AEVA) on murine splenocytes proliferation. AEVA-S and crude protein hydrolysates were fractionated by HPLC and ultrafiltration, respectively. The effect of each fraction on the proliferation of murine splenocy tes was detected by WST-8. The non-protein components were preliminary identified by high resolution mass spectrometry. The results suggested that the stimulated effect of AEVA-S on the proliferation of resting murine splenocytes was more effective than its fractions. Fr. III and IV inhibited ConA-stimulated splenocyte proliferation significantly, and they were preliminary identified as a mixture of bases and nucleotides. Peptide fractions of MW > 10 kDa stimulated the proliferation of resting murine splenocytes and inhibited ConA-stimulated splenocyte proliferation. MW of peptides showed a greater impact on its immunomodulating activity, but did not show a direct correlation. Amino acid composition, sequence and structure of peptides were also important factors affecting its activity.