Analysts polled by Reuters had expected first-quarter gross domestic product (GDP) to expand 4.6% from a year earlier, compared to 5.2% in the previous three months.
The government is aiming for economic growth of around 5.0% for 2024, a target that many analysts believe is ambitious and may require more stimulus.
On a quarter-by-quarter basis, GDP grew 1.6% in January-March, above expectations for a 1.4% rise and compared with a revised 1.2% gain in the previous quarter.
Policymakers are ramping up support for the economy, which has struggled to mount a strong and sustainable post-Covid bounce, burdened by the property downturn, mounting local government debts and weak private-sector spending.