The absorption spectroscopy and three-dimensional fluorescence spectra of human blood were measured and an attempt was made to exploit the endogenous fluorophores of major peaks in the UV and visible light. Fluorescence excitation wavelength range 260-540 nm were used to induce the fluorescence spectra of human blood, and the corresponding emission spectra were acquired from a range starting 20 nm above the excitation wavelength and extending to 780 nm. Fluorescence excitation-emission matrix was used to exploit endogenous fluorophores. The results indicate that the absorption peaks for human blood appear at 274, 345, 415, 541 and 576 nm, and the remarkable emission peaks occur at excitation-emission wavelength pairs of 260-630, 280-340, 340-460, 450-520 nm. According to the previous referenced studies, these fluorescence peaks were attributed to endogenous porphyrins, tryptophan, NAD(P)H, and FAD, respectively. The results obtained can be used to evaluate the distorting effect of blood on the autofluorescence signals of human tissues for optical biopsy.