Maryland's acting Gov. Blair Lee III started off the new year yesterday by shaking hands with 975 Maryland residents at an open house in the governor's mansion in Annapolis. But he had to share the spotlight on the reception line with two other men who, like Lee, want to be elected governor this year and a 106-year-old woman from Glen Burnie.

In his first New Year's Day at the mansion, Lee reinstituted the annual reception. It had been a traditional until last year, when former Gov. Marvin Mandel, now convicted of mail fraud and racketeering, opted not to hold one. New Year's Day 1977 came slightly more than a month after Mandel's first trial on political corruption charges ended in a mistrial.

Despite, the fact that this is an election year and comes just after one of the state's most politically tumultuous years, the majority of the guests yesterday at the mansion were not government officials, but ordinary folks who showed up to wish the new governor well and marvel at splendor of the governor's home.

Lee greeted all his guests with the same folksy manner he's shown at press conferences and community gatherings ever since he became acting governor last August. He deliberately tried yesterday in many cases to turn his guest's attention away from himself and to Annie Duitscher, who was invited to the New Year's reception in return for inviting Lee to her 106th birthday party last September.

Lee constantly told his guests to "Say hello to 'Miss Annie,' and when one woman tried to strike up a conversation with the governor by telling him she knew his father, Lee shot back, "My father is only 85, but Miss Annie has seen 106 new years."

"Miss Annie," who was physically supported on the reception line by Lee's wife Mimi before she requested a chair after standing about an hour, kept asking the governor's wife if it was the end of the line yet.

Although most visitors got a "Hello, how are you? Good to see you, happy New Year" from the governor, some leaned over to Lee and whispered things like "Good luck in the campaign" and "Hope to see you here next year."

"It cheers you up," Lee said later of his well-wishers.

Beside him on the reception line were State Comptroller Louis Goldstein and Maryland Attorney General Francis B. Burch, who are both vying for Lee's job. Lee said he decided to invite both men because "it's customary . . . despite the fact that one (Burch) is actively seeking my job and the other is muttering about it."

But Goldstein and Burch seemed to have recognition problems with the crowd. Goldstein continually had to introduce Burch to people who appeared not to know who they were shaking hands with, while Lee often introduced Goldstein.

Lee said he doesn't expect the new year to be marked by "a lot of (political) infighting" despite the fact that most of his opponents are state government officials. Lee also said he is not facing this year's legislative session "with any apprehension" despite the fact that one of the main gubernatorial contenders is Senate President Steny H. Hoyer.

"I've sat down and talked with Steny . . . he doesn't want to be an obstructionist," said Lee, who wore a blue striped suit, a blue tie with the outline of his state stamped all over it, and a tie clip with the state seal to the reception.

Some of the people who came to the opera house were fulfilling an annusual family tradition, while others said they came for the first time to meet the new governor and see the mansion's 25-foot Christmas tree and the other elaborate Christmas decorations.

"I was just riding by and the line outside looked short so I thought I'd (come in)," said Annapolis resident Guy Goddard, 22, "I'm pretty impressed," Goddard said, he is looked up a winding stairway - covered by a plush Persian tapestry carpet - with leads to the mansion's two upper floors.

New Year's Day is the one occasion when Maryland residents can wander through the reception room, main parlor, main hall and state dining room with their crystal chandeliers, antique clocks, Oriental rugs, Charles Peale portraits, a 19th century French brass and tortoise sitting table, and a 100-year-old grandfather clock which also plays tunes like "Daisy, Daisy." The 106-year-old red and brick Georgian mansion was built by Col. R. Snowden Andrews of Baltimore.