An ebullient Walter F. Mondale received a warm reception in chilly Minnesota today on his first political mission since he became Vice President.

Mondale, a former U.S. senator from Minnesota, stumped through the Red River Valley on the Western border of his native state for the election of Mike Sullivan, the Democrat-Farmer-Labor candidate seeking the House seat vacated when Bob Bergland was named Secretary of Agriculture.

Clearly delighted to be back home, the Vice President laughed and joked with old political frends, sand "God Bless America" with a senior citizens' group, threw snowballs at two fourth-graders who held up a Republican poster in his path, and offered unstinting praise of Sullivan and of Jimmy, Lillian, Amy Carter.

The 35-year-old Sullivan was an aide to Bergland and to Mondale, both of the Democrat-Farmer-Labor Party, when they were in Congress. Although Bergland regularly carried the district by large majorities, the special election Tuesday is expected to be close.

Sullivan has not lived in Minnesota in six years and is not well known here. His Republican opponent, Arlan Stangeland, is a lifelong resident of the district. He is a farmer and a former state legislator.

Traveling by light plane, Mondale stopped in Alexandria (pop. 5,900) and Detroit Lakes (pop. 6,580), both large towns by the standards of this rural area, and ended his tour in Moorhead, a city of 28,000 that is the district's approximation of an urban center. Mondale was met by cheering people at each stop. Despite a wind-chill factor near zero, people lined his path to wave and hold up signs of greetings.

In Alexandria, Mondale bounded onto a wooden platform mounted on bales of hay to tell a group of school children that "Army Carter personally asked me to bring you best wishes from her and her cat Ying-Yang."

Four hours later, in Morehead, he brought similar greetings to senior citizens from President Carter's mother, Lillian. He said her service as a Peace Corps volunteer in India proved that "seniors have a lot to give to this country."

Between a tight schedule and Mondale's story telling, candidate Sullivan had little chance to do anything but stand beaming at the Vice President's side.

Mondale said Sullivan should be elected because "he can walk into my office any time he needs to, he can walk into the Secretary of Agriculture's office . . . and I'll get him in to see the President any time he wants to."

Other members of Congress, Mondale said, could not expect such opportunities.

In a news conference here, Mondale said Carter's decision not to sell concussion bombs to Israel does not indicate any decrease in American support for that nation.

"When the budget is announced in the next few days . . . that will be clear," Mondale said, because Carter's revision of President Ford's budget will include an increase in military assistance to Israel.

Asked about a report that he had been directed by Carter to design a major revision of federal campaign laws, Mondale said administration figures are considering some changes in election laws, including federal funding for congressional campaigns and elimination of a requirement for voter registration prior to election day.

After his campaign swing here, Mondale stopped in Benson, Minn., for the funderal of A.I. Johnson, a pioneer of the Democrat farmer-Labor Party here. Johnson's son Jim is one of the chief staff aides in the Vice President's office.