We can investigate star formation rate by hydrogen recombination lines because young stellar objects (YSOs) ionized the gas around. The free-free emission (at~100GHz) from ionized gas can also trace SFR. Combining information from hydrogen recombination lines and free-free emissions, we can investigate electron temperature. In addition, when we compare the SFR from hydrogen recombination lines without any dust extinction and total infrared luminosity (TIR), we can investigate the time scale of the star formation activities in the galaxies. I will explain the detail for these techniques introducing the ALMA detection of H40a line and ~100 GHz continuum free-free emissions in one merging galaxy NGC3256. Finally, I show the spatially resolve KS relation in NGC3256 that possibly show the regulation of star formation activities due to shock.
