The dye-sensitized solar cells (DSSC) have been regarded as one of the most promising new generation solar cells. Tremendous research efforts have been invested to improve the efficiency of solar energy conversion which is generally determined by the light harvesting efficiency, electron injection efficiency and undesirable electron lifetime. In this review, various characteristics of dye- sensitized nanostructured TiO2 solar cells, such as working principle, electron transport and electron lifetime, were studied. The review avoids detailed mathematical and spectroscopic discussion, but rather tries to summarize the key conclusions relevant to materials design.