Production of new-energy vehicles, medical equipment, intelligent electronic appliances and products related to environmental protection has also grown strongly, according to the NBS.
Behind the fast growth of the high-tech sectors is the 55.3 percent increase in the number of patents approved in the first quarter, Sheng said.
In the Global Innovation Index 2015, compiled by the World Intellectual Property Organization, China ranked 29th, the top notch among mid-income countries, marking China's progress in promoting human resources and research and development, analysts said.
Given those indicators, Sheng said, "We have no reason not to conclude that the Chinese economy has had a good start."
Karlis Smits, senior economist of the World Bank, said, "The GDP numbers in the first quarter indicate that China's orderly transition to slower but more sustainable growth continues."
Zhao Xijun, an economist at Renmin University of China in Beijing, said China's economic upgrading efforts are starting to bear fruit. "The contribution of mid- and high-end industries to GDP growth is increasing," he said.
"The overcapacity of traditional sectors has also been reduced," he added, referring to China's recent move to cut excessive capacity in such sectors as steel making and coal mining. "Economic growth quality is obviously improving."
The 6.7 percent GDP quarterly growth reflects that the economy still faces heavy downward pressure, but "it has remained fairly resilient despite a weak external environment and recent volatility in financial markets," said Smits.
As economic activities continue to pick up in the second quarter, growth may rise to 7.1 percent in the April-June period, said Lian Ping, chief economist of the Bank of Communications.
For the whole year, growth could be 6.7 percent, higher than the minimum set by China's target growth range of 6.5 to 7 percent, said Smits.
"Although rebalancing is proceeding and initial attempts have been made to address overcapacity, credit growth continues to outpace GDP growth and leverage is still building," he said.
"A more rapid restructuring of loss-making enterprises and slower credit growth, combined with stronger fiscal policy action to maintain economic activity, would reduce the associated risks of a disruptive future adjustment."