ALMA's unprecedented sensitivity and angular resolution at millimeter and submillimeter wavelengths will undoubtedly advance the vast frontiers of our knowledge about the universe. I will present expected impacts of ALMA on the studies of star and planetary system formation, in addition to the introduction of its basic capabilities. The sensitivity of ALMA to the optically thin thermal dust emission located at a nearby star forming region 100 pc away is as small as 1/100 of the earth mass in its beam size of ~1 AU, more than 100 times in sensitivity and 30 times in resolution than the currently available radio interferometers. ALMA is also expected to achieve an angular resolution of 0.1 arcsec or better for line observations, revealing detailed kinematics related to planet formation in disks. With such superb capabilities expected for ALMA, I will discuss fundamental questions of star and planetary system formation that we hope to answer with ALMA.