Officers found the 50-year-old victim with a gunshot wound being taken to a hospital by family members just after 10 pm on Canal and 11th Streets.
Investigators say the victim was in a domestic dispute with Sergio Jesus Munos when Munos grabbed a gun and shot him.
Munos, who is from Stockton, was tracked down by Stockton police at his home and arrested for attempted murder.
Further details on the victim's condition were not immediately available.
Anyone with information on the shooting is asked to contact the Merced Police Department at 209-385-4731