The Pennsylvania primary victories of Edward Kennedy and George Bush have lent a new aura of importance to Maryland's May 13 primary contest, reinvigorating the statewide campaigns of the two candidates who are underdogs nationally but are given a good chance of winning here.

"It's going to be a real battle in Maryland now -- a national focus," said Stan Gildenhorn, chairman of Montgomery County's Democratic party, as he watched the televised results from the north Tuesday night to see if Kennedy's early-evening lead over President Carter would hold.

Doran Gunderson, field director for the Bush campaign in Maryland and the District, said that her man's popular victory among Republican voters in Pennsylvania "makes our job a lot easier."

"It buoys people's spirits," she added. "The underlying reason is that they feel what they do is going to count . . . It's terribly important for those who have yet to vote in the primaries to feel that they still will have an impact."

But while the return of hope, expectations and once-discouraged volunteers was lifting spirits in Bush's Silver Spring headquarters, supporters of frontrunner Ronald Reagan were pooh-poohing the notion that anything could stop Reagan's juggernaut. ernaut.

"Since Reagan won in the [Pennsylvania] delegate count . . . I think the whole thing gives false hope to the Bush people," said Forbes Blair, Montgomery County chairman for the former California governor. "It's a nice one-day headline, but I think their exuberance will be short-lived."

Kennedy's forces in Maryland made a point yesterday of comparing the state with Pennsylvania, saying that Maryland shares the characteristics of many of the industrial states where Carter has not fared well.

But Carter supporters countered that the pocketbook issues of soaring inflation and an impending recession that have contributed to the Massashusetts' senator's popularity elsewhere would have less impact here.

"The economic issue in Maryland is important," said Ed Crawford, Carter's statewide coordinator. "But Maryland has an economy that's a little more insullated."

Carter, who lost the 1976 Maryland primary to California governor Edmund G. (Jerry) Brown Jr., this year has won the backing of almost all the state's Democratic heirarchy.

First Lady Rosalynn Carter, Vice President Mondale, and possibly his wife, Joan, are expected to make stand-in campaign appearances for Carter in Maryland early next month.

"Kennedy will probably spend some time in the state," said James Rouse, the millionaire developer of Colombia who is co-chairman of the president's Maryland campaign, "and Pennsylvania showed that personnal campaigning is very effective. It will be a real fight."

At stake in the fight ae 59 Democratic delegates, who will be selected at caucuses after the primary in proportion to the candidates' strength in each congressional district.

On the Republican side, Maryland will send 30 delegates to the national convention in Detroit -- six elected at-large statewide and three each in the state's eight congressional districts.

Bush's strength is concentrated in the urban areas around Washington and Baltimore, particularly in Montgomery County, where one in five of the state's a 419.586 Republicans live and where Bush himself made his home when he was serving as a congressman from Texas.

"You want to go where your strength is," said Peter Tweeley, press secretary for Bush's national campaign effort. "Then you may want to go into some areas where you can pick people off."

For Bush supporters, this would mean trying to slice away some of Reagan's support in the state's most conservative areas -- the small cities and the countryside of western Maryland and the rural Eastern Shore, where popular Rep. Robert Bauman has endorsed Reagan.

Teeley said Maryland would be one of five of the remaining primary states where "we have a good chance" and where the Bush campaign would concentrate its financial resources, adding that "we also have a lot of money on hand and money to spend that Gov. Reagan doesn't.

Reagan campaign officials agreed that they would be working with a paraed-down budget -- probably around $50,000, according to one campaign official -- but said their strategy remains unchanged.

"We're just going to do it with organization," said Bill Lacy, who is runnning day-to-day campaign operations in Maryland for Reagan. "I don't think we're going to change anything now."

Neither Republican candidate, according to members of both camps, has decided when they will start their television campaigin spots or how extensive their media efforts will be.

"My feeling is still that Reagan is going to be the party's nominee," said Allan Levey, the Montgomery County dentist who chairs the state party, and whose son is a Bush youth coordinator. "But what the [Pennsylvania results] do is enhance the position of Bush so he can continue to have an impact on the Republican party."

"Pennsylvania was kind of like the Battle of the Bulge," said State Sen. Howard Denis, a one-time supporter of Sen. Howard Baker. "When someone asked the German general, 'Does this mean the Allies have won or lost the war?' he said, 'It means the war is going to go on.'"