The world's second-largest economy grew 6.9 percent between July and September from a year ago, slightly better than forecasts of a 6.8 percent rise but down from 7 percent in the previous three months.
"That gave the market some hope that we will not see that much of a drag domestically from the overseas slowdown," said Larry Milstein, head of U.S. government and agency trading at R.W. Pressprich & Co in New York.
Treasurys also got lift from data in the National Association of Home Builders' October Housing Market Index (HMI), which showed a three-point jump to 64, a new 10-year high.
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Trading in Treasurys was slow, with few significant U.S. economic reports on tap this week and little news expected from Federal Reserve policymakers contemplating raising near-zero borrowing rates for the first time in nearly a decade.
"The week will be dominated by earnings," Milstein said. "We have about 120 of the S&P 500 reporting this week, and that will be an important driver for our market."
U.S. 30-year bond yields were last fat at 2.88 percent, compared to a yield of 2.86 percent late Friday.
U.S. three-year Treasury notes were up 1/32 in price to yield 0.89 percent from a yield of 0.90 percent late Friday. U.S. five-year notes were down 2/32 to yield 1.35 percent.
The 10-year Treasury note yield was last flat at 2.03 percent.
—Reuters contributed to this report.