In order to reveal proteins differentially expressed in round-headed sperm in human being, two-dimensional gel electrophoresis and mass spectrometry were performed on 30 normal sperm samples from 10 fertile men and 3 sperm samples from a globozoospermic patient. In the range of molecular weight 7.9～93.5 and pI 4～8, altogether (905±57) and (881±32) spots were detected on the 2-DE map of normal and globozoospermic sperms, respectively. 607 spots were matched between the two groups. Mass spectrometry were performed with 16 proteins which were found to be absent in the round-headed sperms and 1 which expressed in a much lower concentration. Altogether 8 protein spots were identified and their possible roles are discussed. Among them, 3 spots were Golgi apparatus-related, 2 spots were subunits of proteasome and 2 spots were zinc finger proteins. Their absence or down-expression possibly interrupt spermatogenic process.