The National Association for the Advancement of Colored People is expected to take aim on the Reagan administration this week as the group begins its 73rd annual convention tomorrow in Boston with more than 10,000 delegates and visitors attending from across the country.

Largely because of problems of the economy and resurgence of hate groups like the Ku Klux Klan, NAACP Executive Director Benjamin L. Hooks has called this year's convention especially important because "despite past progress, these are the worst of times for many black Americans."

This year's convention has two major objectives:

* A national call for more blck voter registration and voting turnout in light of the strengthened Voting Rights Act extension just passed by Congress.

* An effort to bring national attention to the rising problem of black unemployment, especially among young blacks for whom it is expected to reach record proportions this summer.

Hooks has called 1982 "the year of the ballot box."

He said the goal is to "make the voice and strength of black voters known in a manner that has never before been experienced in this nation."

Sen. Edward M. Kennedy (D-Mass.), a likely candidate for the 1984 Democratic presidential nomination, will kick off the convention with an address tomorrow morning, while former vice president Walter F. Mondale, another likely Democratic candidate, will speak later in the week.

President Reagan, who has had major problems with black voters, was not invited to address the NAACP, the nation's oldest civil rights group.

He did speak to last year's convention and received a polite but chilly reception.

NAACP spokesman Denton Watson said the group customarily invites a president only once during his term.

But he added that no invitations have been extended to any other high-level figures in the Reagan administration.

The delegates will be visiting a city that has been plagued by racial tensions and hatred, especially since the start of court-ordered, cross-city busing for school integration in 1974.

Boston Mayor Kevin H. White has asked his city to be "extra sensitive" to racial problems in light of the NAACP convention.

Last Thursday, he created a strategic police unit in a move to head off any racial disorders this summer.

Just two weeks ago the home of a black family in a predominantly white area of the city's Dorchester section was fire-bombed and the family has been moved to another area.

White has said he is afraid of a "long, hot summer" because of high unemployment, especially among black young people, and existing racial tensions in the city. Cuts in federal and city spending have reduced drastically money for youth employment in Boston this summer.

The mayor has assigned 100 policemen to patrol continuously 50 "hot spots" where racial problems are considered most likely to develop in July and August.

White, whose city has not added police to deal with racial problems in previous summers, said, "I didn't really believe the street talk then.But this year I do." CAPTION: Picture, Hooks: "Make voice and strength of black voters know in a manner [as] never before experienced." By Charles K. Crockett for The Washington Post