Provided are a polymer containing a thiophene unit and a thienylenevinylene unit, and an organic field effect transistor and an organic solar cell containing the polymer. The film may be formed by coating a substrate with a polymer containing a thiophene unit and a thienylenevinylene unit using a solution process. Therefore, the production cost may be reduced and a large-scale device may be suitably manufactured since there is no need for an expensive vacuum system to form films. Also, the polymer according to one embodiment of the present invention containing a thiophene unit and a thienylenevinylene unit has very excellent flatness since the thiophene unit is continuously coupled with a vinyl group having excellent flatness. Therefore, the polymer may be useful in further improving the charge mobility since it has high crystallinity caused by the improved ordering property between molecules. Such crystallinity may be further improved by the heat treatment. In addition, the organic compound according to one embodiment of the present invention containing a thienylenevinylene unit may have high oxidative stability because of its high ionization energy.