The Pew study also tracks some divorce trends, citing studies using government data that found overall divorce rates higher for interracial couples.
One study conducted a decade ago determined that mixed-race couples had a 41 percent chance of separation or divorce, compared to a 31 percent chance for those who married within their race.
Blacks are now substantially more likely than before to marry whites.
have climbed to 4.8 million - a record 1 in 12 - as a steady flow of new Asian and Hispanic immigrants expands the pool of prospective spouses.
Another analysis found divorce rates among mixed-race couples to be more dependent on the specific race combination, with white women who married outside their race more likely to divorce.
Mixed marriages involving blacks and whites also were considered least stable, followed by Hispanic-white couples.
"That says a lot about the state of race relations.
As a whole, about 63 percent of those surveyed say it "would be fine" if a family member were to marry outside their own race.
In contrast, blacks who married outside their race increased in share from 15.5 percent to 17.1 percent, due in part to a rising black middle class that has more interaction with other races.
Intermarriage among whites rose in share slightly, while among Hispanics the rate was flat, at roughly 25.7 percent.
"Mixed-race children have blurred America's color line.
They often interact with others on either side of the racial divide and frequently serve as brokers between friends and family members of different racial backgrounds," he said.