the measurement of carrier mobility in organic semiconductor material and device is one of important study contents. the hole-only devices based on the different solvent blends of poly (3-hexylthiophene) (p3ht) and [6, 6]-phenyl c-61-butyric acid methyl ester (pcbm) as acceptor are fabricated, the structures of the devices are all ito/pedot:pss/p3ht:pcbm/au. the hole mobilities in the blend systems with different solvents and various annealing treatments are measured by the space charge limited current method. the results show that the j-v curves of charge transfer in the devices meet mott-gurney equation, the hole mobilities in the active layer with different solvents are different, the active layer formed with high boiling point solvent 1, 2-dichlorobenzene possesses higher hole mobility, heat treatment contributes to the improvement of the hole mobility in the devices. the reason of change of hole mobility is analyzed.