DOME C is advocated as being currently the best astronomical site on Earth, with an excellent duty cycle, excellent seeing (provided that the instrumentation is above the $\sim $30 m boundary layer), low scintillation, low infra red background. There is an opportunity for astronomy projects in the coming years at DOME C. We will review here the case for the extrasolar planet searches. Both transit and microlensing searches for extrasolar planets have a niche at DOME C, but the exact performances of such projects are strongly dependent on the true quality of the site. Transiting hot Jupiters could be efficiently detected thanks to the excellent duty cycle at DOME C. The case of hot Neptunes is not clear. Frozen 1–15 Earth mass planets are detectable with dedicated microlensing operation, either by concentrating on a high magnification events alerted by temperate sites, or a wide field imager on a 2 m class telescope to simultaneously detect and monitor microlensing events. In order to run detailed simulations of observations of these projects, we have a critical need of seeing statistics, and in particular about the behavior of the boundary layer above the ice sheet and its influence on the resulting seeing.