Rapid and selective enrichment of phosphopeptides from complex biological samples is essential and challenging in phosphorylated proteomics. We present the direct growth of the ultrathin YPO 4 shell on the surface of polyacrylate capped secondary Fe 3 O 4 microspheres (PA-Fe 3 O 4 @YPO 4 ) for the rapid and selective trapping phosphopeptides from complex samples. The prepared PA-Fe 3 O 4 @YPO 4 could be rapidly harvested in the presence of an applied magnetic field and easily re-dispersed in solutions after removing the external magnet. The ultrathin YPO 4 shell on super-hydrophilic PA-Fe 3 O 4 has the advantages of fast adsorption/desorption dynamics and low non-specific adsorption, thus trapping of phosphopeptides from the tryptic digests mixture of β-casein/BSA with molar ratio of 1/300 is achieved in 20s adsorption/desorption time. Two phosphopeptides can still be detected with a signal to noise ratio (S/N) over 3 when the amount of β-casein was as low as 8fmol.