A House subcommittee chairman said yesterday his panel will investigate Interior Secretary James G. Watt's use of privately donated funds to pay for two recent social functions at Arlington House, the historic home of Robert E. Lee.

"I find it hard to believe that people and corporations who made contributions intended them to be used for the private entertainment of James Watt and his friends," said Rep. Edward J. Markey (D-Mass.), chairman of the Interior Committee's subcommittee on oversight and investigations. He called Watt's use of the funds "arrogant."

Markey said any contributions from corporations "probably were claimed as tax deductions. Therefore, the American taxpayer may have paid for the Watt cocktail party."

Interior Department spokesman Harmon Kallman yesterday declined to comment on Markey's statements. "Since there's going to be an investigation, I guess we'd better not," he said.

A department spokesman said Wednesday that a National Park Service "voluntary donation fund" was used to pay for the two occasions, a breakfast hosted by Watt's wife on Dec. 14 and a cocktail party three days later. Both functions were held in the stately, publicly owned Custis-Lee Mansion overlooking Arlington National Cemetery.

The department has said it is unable to determine how much the two affairs cost because bills are still coming in. Kallman said yesterday he also could not say who attended the functions because "I don't have access to the guest lists."

Kallman said the events were "semiofficial occasions meant as thank-yous for kindnesses shown and help given to Interior during the year" and were attended by high-level officials of Interior, the White House and other government agencies.

He also said he believed that no one outside of government was on the guest lists.

Watt's use of the Lee memorial for social events also has drawn criticism that such functions are inappropriate in a government-owned, historic setting. Eleanor Templeman, historian of the Society of the Lees of Virginia, said yesterday the house--once owned by Lee's father-in-law and then by Lee's wife--is considered "a shrine" to the Confederate hero.

Markey said the investigation, scheduled to start next week, should find out who contributed to the fund, what purpose they thought the funds would be used for and who has benefited from the use of the funds.

The proposed federal budget says the Interior secretary "accepts and uses donated moneys for purposes of the National Park System" but gives no details on the source of contributions. It puts anticipated donations for both fiscal 1981 and the new fiscal year at $1.5 million annually.

Interior spokesman Kallman said yesterday the $1.5 million figure "sounds pretty high," but said he was unable to determine immediately the amount of such funds available to Watt.

Congress traditionally appropriates a relatively small amount to Cabinet secretaries for entertaining. One House staff member said yesterday Watt had received $3,000 to $4,000 for that purpose.

Kallman was quoted by United Press International as saying that Watt is not wealthy, does not drink and did not want to see tax funds underwriting a party. "I've really never seen so much made out of such small potatoes," Kallman told UPI.

Another Interior spokesman, Douglas Baldwin, said on Wednesday that Watt decided not to hold the parties at the Interior Department because of "a desire to have a place where people could be served liquor. The secretary didn't feel it was appropriate to have liquor served in a government building."

Several Interior spokesmen said similar social functions have been held over the years by previous Interior secretaries who also used voluntary donations to pay for the occasions.

That was disputed yesterday by Cecil Andrus, who held the post during the Carter administration. "No, it was not our practice," said Andrus in an interview from his home in Boise, Idaho. "This administration seems to have donated funds for use whenever they want them."

Andrus said he was unaware of any funds donated from outside sources during his tenure as secretary. Andrus said he used money from his congressionally appropriated entertainment fund to host visiting Polish miners and other foreign visitors.

Andrus also recalled he had been approached at one point for permission to use the Lee mansion for a social function. "We said,'No,' " he said.