The PV cells and thermal collector are integrated into a system to form the photovoltaic-thermal (PV/T) collector, and nanofluid is utilized as a coolant to decrease temperature of photovoltaic cells (PV). This work is aimed at the numerical analysis of a PV/T collector using nanofluid. For acquiring more results about the effects of operation parameters on performances of PV/T collector, the mathematical models of PV/T collector are proposed. In this work, the influences of nanofluid type and volume concentration on PV conversion efficiency, PV cell temperature, thermal and electrical power are investigated. The effects of PV collector parameters on the performances are also analyzed and discussed. The results indicate that the performances of PV/T collector with A1(2)O(3) /water nanofluid are better than that of the PV/T collector using TiO2/water nanofluid. When mass flow rate of nanofluid is 0.03 kg/s, the electrical power of the PV/T collector is much higher than that of the PV/T collector when mass flow rate of nanofluid is 0.0005 kg/s, 0.001 kg/s and 0.01 kg/s. As mass flow rate of nanofluid is 0.03 kg/s, the thermal power of the PV/T collector is 12.11% higher than that of the PV/T collector as mass flow rate of nanofluid is 0.0005 kg/s. When the channel height decreases, the removed heat of the PV/T collector by the nanofluid increases, the largest thermal power difference of the PV/T collector between 0.005 m and 0.015 m tube diameter is 24.00 W.