The Chinese HSBC services PMI increased to 52.9 in April from 52.3 in March.
A reading below 50.0 indicates contraction.
The increase was driven by higher new orders and employment in the service sector.
"The latest set of PMI data indicated that Chinese service-sector companies had a strong start to the second quarter, with activity and new orders both rising solidly in April," the HSBC's chief economist for China Qu Hongbin said.