Haidian district in Beijing, home to technology hub Zhongguancun, has become a pioneer of scientific and technology innovation for China during the 40 years since the start of the country's reform and opening-up.

Nearly 40 unicorn companies－startups worth more than $1 billion－in addition to 300 listed firms and 20,000 high-tech companies are located in Haidian, which at 594 billion yuan ($85.6 billion) had the highest GDP of the 16 districts in the capital last year.

Since 2016, Haidian has been contributing the most to the city in terms of economic growth.

"Once we returned to China after graduating from colleges in the US, the first place we thought of to set up our company was Haidian," said Lin Fan, who leads a team on artificial intelligence applications research.

Lin said Haidian's top talent, great innovation facilities and government policies helped him and his team choose the district as the starting location of its business dreams.

In the past few years, Haidian has been carrying out various preferential policies for science and technology innovation. It has been investing increasingly to attract companies to set up offices and to support research and innovation centers.

An innovation fund co-invested by the district government, private companies and a natural science fund－the first of its kind in Beijing－will invest 30 million yuan this year to help innovation research teams.

"We hope that our government can share more of the startup risks at their early stage, including fundamental research, proof of concept, incubation and bringing the product to market," said Yu Jun, Party chief of Haidian district.

He said the government will provide a full chain of services to support research teams and startups.

"Starting from this year, we plan to select 20 projects annually from the public and provide a subsidy of up to 500,000 yuan each to support early stage research," he said. "At the same time, we will invite scientists, business leaders and investors to be mentors for those projects."

Seeing modern office buildings and high-tech centers in Haidian, especially in the Zhongguancun area, it's hard to imagine that decades ago, the place was full of crowded electronics wholesale markets.

The district started reconstruction in 2010. According to the Haidian district government, the western Zhongguancun area has removed 600,000 square meters of electronics wholesale markets and consumer areas and introduced 59 incubators such as innovation workplaces and six unicorn companies including Ofo, NIO and Rong360.

Ding Zhe, 43, a Beijinger who used to live in Haidian, said there were not too many companies in the district when he was young.

"It has been growing rapidly, especially in the past eight years, as innovation became the economic driver in the area," he said. "I still remember the time I bought computer components and made one by myself in Zhongguancun. It's totally different now, but I like how it's going."