A composition for solar cell electrodes includes a conductive powder, a glass frit, an organic vehicle and a thixotropic agent, and has a first thixotropic index (TI I) of about 1.5 to about 4 as represented by the following Equation 1, and a second thixotropic index (TI II) of about 4 to about 8 as represented by the following Equation 2, both the first thixotropic index and the second thixotropic index being measured at 23° C. by a rotary viscometer. [Equation 1] TI I=(viscosity at 1 rpm/viscosity at 10 rpm) [Equation 2] TI II=(viscosity at 10 rpm/viscosity at 100 rpm).