Stephen Schwarzman is shepherding the Blackstone Group’s initial public offering toward completion and fending off a tax law change in Washington that could cost him billions of dollars. But he plans to spend tonight at the library.

The New York Public Library, that is, where Mr. Schwarzman, who will receive $677 million in cash and retain a 23% stake in Blackstone worth about $7.5 billion after the public offering, is scheduled to be the honoree at tonight’s annual corporate dinner.

At least some of the 400 guests expected to be in attendance may be wondering whether Mr. Schwarzman will join the ranks of Bill Gates, Warren Buffett, and Michael Bloomberg, some of the richest men in America who are giving away their fortunes to charity.

Though he is the chairman of the board of trustees at the John F. Kennedy Center for the Performing Arts in Washington, D.C., and on the boards of the New York City Ballet, the Film Society of Lincoln Center, the Frick Collection, and the New York Public Library, Mr. Schwarzman, 60, is better known for his birthday party in April that cost $3 million and his 24-room duplex apartment inside 740 Park Avenue. He did not appear on the Chronicle of Philanthropy’s list of top givers last year. But those who know him say that in recent years he has been raising his profile on the charitable scene.

“We are recognizing him as a figure in the business world, but part of that is the role he plays increasingly in cultural organizations in New York,” the president of the New York Public Library, Paul LeClerc, said. Mr. Schwarzman has been active with the library since 2001.

The $2.2 million raised by the dinner will go to the research libraries, Mr. LeClerc said. The co-chairmen are J. Tomilson Hill, a vice chairman at Blackstone, and James B. Lee, Jr., a vice chairman at J.P. Morgan Chase and Co. Humorist Calvin Trillin and a CNBC anchor, Maria Bartiromo, will speak.

Mr. Schwarzman and his wife, Christine Hearst Schwarzman, have become regulars at events like these, and increasingly of late, honored guests. He was given the Leadership Award at his alma mater, Yale University, on Thursday night. Columbia University’s National Center on Addiction and Substance Abuse awarded him with a Distinguished Service Award in April of last year.

Mr. Schwarzman declined to be interviewed through a spokesman. The company’s executives are in a Securities and Exchange Commission-mandated quiet period before the initial public offering.

The author of a book about the newly wealthy, “Richistan,” Robert Frank, said that after making billions of dollars many people start to work on their legacy.

“The amount of money you have becomes less important than your impact on the world,” he said, adding that in today’s social climate, “You really have to give it away to be socially accepted.”

Mr. Buffett pledged $30.7 billion to the Bill and Melinda Gates Foundation last year, and another $6.7 billion to other funds. Carl Icahn, currently listed as the second richest person in the city, has made charter schools a priority of his philanthropy.

“At the moment he is a guy who is seeing opportunities and taking them,” the author of a book about 740 Park Ave., Michael Gross, said of Mr. Schwarzman. “The question remains: will he see a chance to give back, and will he take that opportunity with the same alacrity and dedication that he showed in making all that money?”

Mr. Gross said that the public sale of Blackstone could mark Mr. Schwarzman’s crossover into the third phase of his life — philanthropy. Like the previous owner of his apartment, John D. Rockefeller, Jr., Mr. Schwarzman could become a major figure in the city’s arts and charity organizations.

A native of Philadelphia, Mr. Schwarzman has three children with a previous wife, Ellen James Philips, whom he met while at Harvard Business School.

The attention to Mr. Schwarzman’s wealth is fueling a movement in the Senate to change the way private equity firms are taxed.

“We’re seeing right now some of the potential backlash from realizing how much money these people make,” a professor of finance at New York University’s Stern School of Business, Kenneth Froewiss, said. “It makes it a tempting political target right now.”

On Thursday, Senator Grassley, a Republican of Iowa, and Senator Baucus, a Democrat of Montana, introduced a bill – already referred to as the “Blackstone Bill” — that would require publicly traded partnerships to be taxed at the corporate tax rate.

Mr. Schwarzman and his partner and co-founder, Peter Peterson, founded Blackstone in 1985 with $400,000. Among the companies Blackstone owns are Madame Tussaud’s, United Biscuits, and Pinnacle Foods, which makes Aunt Jemima pancake mix. The company has had a 30.8% annual return on private equity funds since 1987, according to the SEC filings, though returns in private equity are hard to compare with other assets because of differences in how they are measured.