At what age do people become entrepreneurs? A Harvard Business School study suggests that 42 is the magic age of successful startup founders.

In China, research by the Chinese Academy of Social Sciences shows nearly 40 percent of entrepreneurs start their businesses between the ages of 36 and 44.

"The younger generation is optimistic that the rapid technological advances offer them opportunities. They have more tools to lower costs and boost efficiency," said Ju Jinwen, an economist at the CASS.

China Daily talked with four successful entrepreneurs who started their businesses at a young age.