Abstract　 　　
  The star formation rate (SFR) is one of the most fundamental properties of galaxies. The accuracy of the estimation of the SFR directly affects our understanding on how galaxies assemble their mass. Although SFR can be traced using ultraviolet (UV)/optical emissions from OB stars, the estimation has large uncertainties due to the dust extinction. The dust grains absorb energy from UV bands and then re-emit it at infrared (IR) bands. Therefore, multi-wavelength data including UV and IR observations have great advantage in studying the SFR as well as the dust extinction. Using UV and IR data, we studied the SFRs and dust attenuation of merger galaxies, we also re-built the IRX-beta relation. In this talk, I will (1) summarize the methods to calculate the SFR of galaxies, (2) introduce our SED fitting code (CIGALE, Code Investigating GALaxy Emission), and (3) present our recent work on SFRs and the dust extinction of galaxies .