Objective To detect the function of proteolipid protein (PLP) peptide (residues 56-70)-specific CD4+ T cells in experimental allergic encephalomyelitis (EAE) in Biozzi AB/H mice (H-2Ag7). Methods Biozzi AB/H mice were immunized by synthetic PLP56-70 peptide (DYEYLINVIHAFQYV) which was emulsified by sonication with complete Freunds adjuvant, a EAE model proven histologically and clinically. Murine splenocytes and spinal cord infiltrated (SCI) T cells were stimulated by PLP56-70, then the CD4+ T cells were isolated by Dynabeads, and confirmed by staining with anti-CD4 antibody. Finally, the IL2 bioassay and IFN-γ/IL4 ELISA were done to detect T cell proliferation and cytokine secretion after PLP56-70 stimulation.Results The histology of murine spinal cord showed a great number of lymphocytes infiltrated the spinal cord; the clinical signs showed high scores (4.3) on the peak, as well as a good EAE model. After being isolated by Dynabeads, CD4+ T cells showed high purification (>99%) by staining with anti-CD4 antibody. IL2 bioassay showed that those T cells were PLP56-70 -specific T cells. ELISA showed that those T cells had high IFN-γ/IL4 ratio, indicating that they are T helper 1 (Th1) cells. Conclusions PLP56-70 -specific splenocytes and SCI CD4+ T cells in EAE from Biozzi AB/H mice were detected and showed that both of them were PLP56-70 -specific Th1 cells. It is beneficial to understand what kind of role these T cells play in the development of EAE.