The coupling of capillary electrophoresis to electrospray Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR-MS) was presented for the on-line separation and detection of mixture of peptides. With the ultra-high resolution and unmatchable mass measurement accuracy FT-ICR-MS provides, the separation and identification of angiotensin III, octreotide and elastin chemotactic were successfully achieved using this fabricated device, which showed its great application potential in detection and structural identification for multicomponent sample. The coupling of capillary electrophoresis to electrospray Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR-MS) was presented for the on-line separation and detection of mixture of peptides. With the ultra-high resolution and unmatchable mass measurement accuracy FT-ICR -MS provides, the separation and identification of angiotensin III, octreotide and elastin chemotactic were successfully achieved using this fabricated device, which showed its great application potential in detection and structural identification for multicomponent sample.