At the present time a few low mass exoplanets have already been detected in the so-called habitable zone (HZ) of their host stars. On one hand a limited number of planets with a few times the mass of the Earth orbiting bright stars in the solar vicinity have been characterized. However measurements of transiting super-earths seem to indicate that these planets could have massive atmospheres and may not be optimum for life development. On another hand, a large number of exoplanets with radii comparable (or even smaller) to the Earth's one have been identified by the Kepler space mission. However these potentially rocky planets are not in the HZ . In addition the host stars of these planets are faint and at quite large distance: A difficult situation for further studies as mass determination or differential spectroscopy during transits. In this lecture we will discuss the perspectives in that exciting search towards the discovery of potential sites for life development.