"We want to build and strengthen this friendship to benefit the people and companies of both cities and ensure international cooperation between Houston and Shenzhen," said Doreen Dai, chief representative of the North American Representative Office of Shenzhen.

Li Shi, deputy director-general of government agency Invest Shenzhen, described Shenzhen as a "wonder city" that has grown from a small fishing village of 30,000 to a vibrant metropolis of more than 10 million people and one of China's largest import/export cities.

"Shenzhen is diversified and has become the city of innovation in China," Li said. "The city of Houston has consistently seen innovation in its business environment. It's at the top of the innovative force in China."

Shenzhen, strategically located just north of Hong Kong, is working to promote more innovative technologies, participate in strategic industry, and become a leader in the financial sector, just as it has become a force in internet technologies. Last year, Shenzhen's GDP surpassed $200 billion, Li said.

Just as Shenzhen has grown into one of China's major cities in the past 30 years, Houston has emerged as a world leader in energy, said Cao Derong, commercial counselor of China's Consulate-General in Houston.

"I think that both cities can create a new level of cooperation," Cao said.

Shao Ting, director of communication and marketing for Invest Shenzhen, said, "The relationship between Houston and Shenzhen is key to the diplomatic international relations between the two (giants)."

According to the Houston Shenzhen Sister City Association's brochure, Houston and Shenzhen have been exchanging cultural, education, and social and economic information since 1984, formalizing the Houston Shenzhen Sister Cities program five years later when a delegation from Shenzhen traveled to the States.

In 1994, a Houston delegation, including a high school football team, visited Shenzhen to participate in the Lychee Festival and provide an exhibition American football game. Since then, there have been several visits between city delegates, including mayors and business leaders.

Shao said Shenzhen, ranked second in Forbes magazine's 2012 list of innovative mainland cities, is home to many Fortune 500 companies.

In 2012, Shenzhen spent 3.81 percent of its GDP, or 49 billion yuan (about $8 billion), on business development and has had more Patent Cooperation Treaty applications than any other Chinese cities for nine consecutive years.

Shenzhen is described as a melting pot of cultures, an eco-friendly environment and a city that has accelerated growth in six emerging industries, including biology, the internet, new energies, new materials, information technology and cultural and creative industries.

"I had the opportunity to visit Shenzhen a few years ago, and I was very impressed ... Mostly because there were so many similarities (with Houston), including the city's humble beginnings to becoming a dynamic, modern metropolis," said Houston Vice Mayor Ed Gonzales.

There were similar demographics between the two, he said, such as the young population of business professionals that are in evidence in both cities.

"Both have an established market that is ready for investment," he said.

During the forum, letters of investment cooperation were formally signed between Invest Shenzhen and two Houston firms, BioHouston, Inc., and OMP Enterprises.

"We really want to encourage cooperation and friendship." Gonzales said.