The quantum properties of entangled biphotons generated via frequency-nondegenerate type-I Spontaneous Parametric Down-Conversion (SPDC) were studied in theory, and compared with that of frequency-degenerate type-I SPDC. The properties of spectrum and entanglement of entangled biphotons in both cases were analyzed by the joint spectral intensity; the property of quantum interference was given by the results of Hong-Ou-Mandel interferometer and Mach-Zehnder interferometer. The results show that, for pulse pumping, the phase-matching function is shown to be asymmetric as a result of frequency-nondegenerate, which leads to entangled biphotons distinguishable and quantum interference visibility was reduced. As the pump bandwidth is increased, this effect becomes more pronounced. For monochromatic pumping, the phase-matching function is shown to be symmetric, which results in maximum entanglement and quantum interference visibility. These results provide a theoretical basis for the applications of frequency-nondegenerate entangled photon source in various quantum information schemes.