There are close relationship between physiological properties of glottis and vocal tract and the age and gender of a speaker. Since physiological changes in glottis and vocal tract affects the voice of a speaker, the features obtained from speech signal can be used to determine the age and gender. In this study, the relation between the gender of a speaker and voice source occurred in glottis is investigated. For this purpose, the TIMIT database is used consisting of 438 male and 192 female speakers. The voice source of each speaker is obtained from the /a/ phoneme of each speech by inverse filtering. CIQ, SQ and dH1H2 parameters calculated from the voice source are used with respect to a threshold value to determine the gender of the speaker. In this study, 99% success for CIQ, 97% success for SQ and 94% success for dH1H2 are obtained.