HAVANA, Cuba — Yibo Shen came to Cuba five years ago to study Spanish at the University of Havana.

He's still here, working and passing time in Chinese restaurants on the weekends, one of a growing number of Chinese who are living here as Cuban-Chinese trade booms.

China is now Cuba's second-largest trading partner, after Venezuela. Trade between Cuba and China soared last year to $2.4 billion, Ricardo Alarcon, Cuba's national assembly president, said during a recent trip to China.

China's oil company is exploring offshore oil and Chinese businesses are flourishing. Inexpensive Chinese sneakers and auto parts fill Havana's bare-bones shops and Chinese pharmaceuticals are being developed in ventures with Cuban firms.

"We expect a substantial increase in Chinese visitors to Cuba," Alarcon said in China. China's Xinhua news agency reported in March that 10,000 Chinese visit Cuba each year.

A 45-year trade embargo prevents most U.S. businesses from trading with Cuba, and a U.S.-imposed travel ban keeps most Americans from visiting the island. But the Chinese have no such difficulties.

Shen, for example, represents one of China's largest bus manufacturers, the Yutong Group. In just a few years here he's sold thousands of Chinese buses as replacements for a tattered fleet that largely had succumbed to age and a lack of spare parts.

"Every day more Chinese companies come here to invest and sell things, much more than four years ago," he said in fluent Spanish.

Sitting in a Chinese restaurant in Havana's old Barrio Chino, once the largest Chinatown in Latin America, Shen, who hails from Shanghai, ate ribs and chatted in Mandarin with two Chinese women. They were midlevel Spanish students at the University of Havana, where many Chinese people are studying.

Ivana Cho, who's also from Shanghai, said she wanted to do postgraduate work in Cuba in tourism or economics.

How many Chinese students are studying in Cuba is uncertain. Neither the Chinese nor the Cuban government is willing to provide such information. But there's little reason to doubt that the number is growing. Both governments are eager to see the long relationship between the countries grow. Cuba was the first Latin American country to recognize the communist takeover of China in 1949.

When Alarcon spent five days in China earlier this month, he visited Shanghai, China's financial center, and the rapidly expanding commercial region of Guangdong.

Not only Chinese business has made inroads in Cuba. Chinese culture has seen a renaissance in the Barrio Chino as well, after many years of decline.

At an early-morning Chinese exercise class in an open-air kung fu studio in Havana's Chinatown, more than 100 Cubans practiced qi gong, many of them wearing Beijing 2006 T-shirts from a China trip they took last year.

Such tai chi and kung fu schools have spread to towns across the island, with an estimated 5,000 practitioners.

The cultural exchanges go both ways.

"Last year the world-famous Shaolin monks came, and one morning they made a very impressive demonstration in the City of Sports," Havana's athletic stadium, said Serafin Chuit, a Cuban of Chinese decent.

A few hundred thousand Chinese laborers were brought to Cuba starting in 1847. They built a thriving neighborhood outside the walls of old Havana and blended Chinese and Afro-Cuban culture, fighting in Cuba's independence wars and in the 1959 Cuban Revolution, Brown University professor Evelyn Hu-DeHart said.

After Fidel Castro took power in 1959, many Chinese-Cubans lost their small businesses as the new government nationalized the economy. Many left for the United States and elsewhere in Latin America.

But not all.

In a Chinese senior center across the street from the kung fu studio, Abel Fung recalled how he lost his small shop after the revolution. He eventually went to work as a machinist in a government shop.

"I had my business, it was going well, but they nationalized me," Fung said. "I lost everything." He stayed because of family.

Over the years the Barrio Chino lost much of its Chinese flavor, but an infusion of tourism and now a new generation of Chinese are bringing back the ethnic feel.

Tao Jin Rong, a prominent businessman in the Barrio Chino, came to Havana in 1995 to open a restaurant.

"I am Chinese-Cuban, a Chinese person born in Shanghai, but I live here in Cuba permanently," Tao said.

His restaurant, Tien Tan, which operates under a special license from the government, gets high marks from Cuba's burgeoning Chinese community.

But while neighboring restaurants compete for business, there's little true capitalism being practiced in the barrio. None of the businesses are truly independent, said Roberto Vargas Lee, the vice president of the Cuban Federation of Martial Arts.

"All of the Barrio Chino is registered with the state, under a very important principal: the development of culture," he said. "It is not that in the neighborhood there is some form of capitalism or that we are establishing a trend of restaurants and businesses that think they are independent, not at all."

And tourists remain the biggest customers for the Chinese restaurants. Few Cubans can afford them.

That's something that Tao hopes will change.

"Cuba needs to find its Chinese food again," he said.

(Hoffman is a McClatchy Newspapers special correspondent. Tim Johnson contributed to this report from Beijing.)