Nearly four out of every 10 Chinese business people feel they were under serious stress despite their happiness improving each year, a recent survey has found.

The survey, conducted by Forbes China, found the happiness index of Chinese entrepreneurs increased from 7.8 in 2011 to 9 this year, an indicator that the majority of them are optimistic.

But the survey also discovered that nearly 40 percent were under pressure and one third felt stressed. Career, responsibility and social factors are major contributors to the mounting pressure they are under.

Shi Guowei, research director of Forbes China, said Chinese entrepreneurs are more troubled by mental stress nowadays.

He said male entrepreneurs were found to be under more pressure than their female peers.

Entrepreneurs in the east of China are happier than those in other regions but also suffer from higher stress, according to the survey.

An IT entrepreneur, who declined to be named, said heated competition is a constant for any company trying to grow in the industry.

"If we don't grow fast, we will be eaten alive," he said. "When we are bigger, many competitors will start to trap us."

Talent shortage is also a bottleneck for many small and medium-sized companies.

"We have not grown strong enough to hire professional management to run the company, so I have to be here all the time to look after everything," the IT entrepreneur said. "It is really hard to compete for talent with established giants."

Mike Thompson, professor of management practice and director of the Center for Leadership and Responsibility at China Europe International Business School, said the huge growth of Chinese entrepreneur activity is partly fuelled by angel investors and venture capital investors who are seeking China-based start-up companies in which they can invest.

Many of these start-ups, however, are failing.

"We have witnessed failures because people are rushing into entrepreneurship, when it is not really their calling," Thompson said. "Beyond that survey, it shows me that many people are not living out careers according to their calling."

He advised entrepreneurs and business people to be true to themselves in personal reflection and conversation to close the "gap of stress" created by trying to perform.

The Forbes survey interviewed entrepreneurs from 36 cities in China. About 71.3 percent were male.

The survey found that a good family brought more happiness to male entrepreneurs than their female peers. Other factors affecting happiness levels varied from age group to age group, the survey found.

Those between the age of 21 and 39 were more occupied with setting up and developing their career, while entrepreneurs between the ages of 40 and 59 were more focused on their family life.

Respondents above the age of 60 enjoyed more of peace mind.

Most entrepreneurs who responded to the survey prioritized family, career and health over wealth.

Travel, study and charity were cited by most entrepreneurs as interests, with nearly 90 percent of respondents finding satisfaction from charity events, according to the survey.