Dark starspots and bright facula are due to magnetic activity on the surface of stars. These features induce inhomogeneous fluctuations in a star light curve and one can find the rotational period of the star from these rotational modulations. The time evolution of these fluctuations might provide useful information regarding the magnetic activity. We define two quantities to study the magnetic activity quantitatively and apply them for a sample of G-type Kepler targets. One of these quantities measure the stability of magnetic features and another one tells us the size of them. Then we calculate the correlation of these quantities and finally compare our results with the Sun. These results open a window to understand how magnetic activities behave over distant stars.
