Internet mogul Jack Ma and property tycoon Wang Jianlin are wrestling for the top spot on China’s billionaire list this year.

Both men will benefit from initial public offerings this year. Alibaba Group Holding Ltd. ’s $21.8 billion share offering in New York in September vaulted Mr. Ma into the top spot. However, Mr. Wang’s flagship company, Dalian Wanda Commercial Properties Co., is set to start trading in Hong Kong on Dec. 23 in a $3.7 billion IPO. If Wanda shares rise 30% in their debut, Mr. Wang will reclaim the title of China’s richest man, according to Hurun China Rich List, which tracks Chinese wealth.

“The private sector is very dynamic,” said Rupert Hoogewerf, founder of Hurun China Rich list. “The fast-changing list shows the private sector is not yet mature.”

The competition between the two men is increasingly intense because, as with many entrepreneurs in China, they are diversifying their businesses—and invading each other’s turf in the process.

In August, Dalian Wanda Group Corp. launched a venture with Alibaba’s arch rivals,Tencent Holdings . and Baidu Inc. The goal is to bring some of the offline traffic Wanda enjoys as China’s largest shopping-mall operator to the online world. Alibaba made itsfirst bricks-and-mortar investment in March this year, plowing $692 million into Intime Retail (Group) Co. , which operates 36 department stores in China.

For Messrs. Ma and Wang, the competition is personal. In 2012, on national TV in China, they made a bet of 100 million Chinese yuan (US$16.1 million) over whether online or offline shopping would control the majority of the market by 2020. Mr. Wang later indicated the bet was a publicity stunt suggested by TV producers, but it has served to highlight the direct competition between the two men.

Both are old by China billionaire standards—the average age of Chinese billionaires is 40, according to Hurun. Mr. Wang, 60, who joined the People’s Liberation Army as a teenager, has said he would retire in 2020 to work on poverty relief. Mr. Ma, 50, gave up the CEO role last year and is now the executive chairman and public face of Alibaba, zipping around the world for technology events, philanthropic missions and new ventures.

“Wang Jianlin’s old age may look like a weakness, but he is good at learning and not afraid of making changes,” said Qian Shizheng, a professor in the business management school at Fudan University in Shanghai.

Mr. Wang encourages his managers to read “Das Kapital”, Karl Marx ’s critical analysis of political economy. His takeaway from the book is that as people get richer, the things they value will change.

That is one reason behind Mr. Wang’s push into entertainment. Wanda has plans to build up to 10 major amusement parks in less than a decade. Wanda has China’s biggest theater network and the largest karaoke chain. Mr. Wang launched a movie studio in 2013, and has collected art works which the company says are worth more than 10 billion yuan. A museum will open in its new Shanghai headquarters to showcase his collections.

Mr. Ma is also pushing into entertainment, by investing in a football team, video and media companies this year. He is seeking partners in Hollywood for more content.

In the past, Chinese billionaires tended to shy away from the limelight and didn’t want to be included in the billionaires’ list. Now they see this as a good marketing opportunity, as their businesses become more global and finances more transparent as public companies.

These entrepreneurs are just as politically savvy as managers of state-owned companies, but are much more commercially driven and innovative. Beijing is actively trying to reform many of these SOEs, which have traditionally received preferential treatment and done the bidding of the government

Both Messrs. Ma and Wang owe some of their success to the Chinese government. Beijing has allowed Alibaba to bring disruptive innovation to state-owned industries such as banking, while the company has helped boost Chinese consumer spending and nurtured grass-root entrepreneurship on its Taobao site. Mr. Wang built his empire on cheap land from local governments. In exchange, he built new city centers that help drive GDP growth.

The two come from different backgrounds. Mr. Wang worked in government and his father was a senior official in Tibet and Sichuan province. He runs his company like a military operation, separating the two-year construction of massive shopping malls into detailed steps to make sure that they won’t be delayed by a single day. His managers must wear a suit and tie at work.

Mr. Ma comes from more humble upbringing and worked as an English teacher and tour guide.

This helps explain their different share holdings of their companies. Less than 100 of Wanda’s 90,000 employees own shares. The majority of Alibaba’s roughly 20,000 employees own shares or options, and Mr. Ma’s share in Alibaba Group is less than 7%.

“Jack Ma comes from a more humble background than Wang Jianlin, so he is more willing to share,” said Oliver Rui, a professor of finance and accounting at the China Europe International Business School in Shanghai.