Rep. Les Aspin (D-Wis.), serving notice that the House Armed Services Committee will be more active under his chairmanship, announced yesterday that it will investigate whether the country has received its money's worth from the $1 trillion military buildup of the past four years.

The newly elected chairman said he believes that the money may not have been spent as wisely, or with as coherent a strategy, as it should have been.

"We're saying, we've spent a trillion dollars," Aspin said. "Before we give you a few hundred billion more, tell us what you did with the trillion."

Some critics have accused Defense Secretary Caspar W. Weinberger of increasing his department's budget without a coherent strategy. Weinberger has responded that the military must be prepared to fight in any part of the world and in more than one place at a time and that it was in such poor shape in 1981 that he had to concentrate on all areas: nuclear and conventional, personnel and weapons.

The committee's action confirms what many observers predicted earlier this month when Aspin, 46, deposed Rep. Melvin Price (D-Ill.), 80, as chairman: that the House Armed Services Committee, traditionally the Pentagon's best friend in Congress, will take a more critical view of Defense Department proposals.

Many of the Democrats who upset the seniority system by deposing Price and elevating Aspin above a handful of more senior Democrats said they believed that the committee should examine broader issues of strategy and spending priorities rather than the nuts and bolts of military hardware that has been the committee's primary interest.

"Basically, the trouble with the Armed Services Committee is that it treated defense too much like public works," one member said.

Aspin said the committee will hold hearings during the spring with witnesses from inside and outside the Reagan administration. He said the hearings will help the committee act rationally as it cuts and reshapes the administration's proposed $314 billion military budget for next year and in future years.

Weinberger will be permitted to lay out his budget proposal in the traditional way when he appears before the committee next week. But the committee will begin a more critical examination of the administration's goals in mid-February, Aspin said.

"During the first four years, we didn't have much luck in getting them to lay out their priorities," he said. "We didn't succeed in getting them to lay out a coherent position of where we are going and how are we going to get there.

"Now we're saying, it's time to be more specific," Aspin said.

"We have to realistically presume that dollars are not going to be as easily come by" in the next four years, he said, so setting priorities becomes more important.

"There is some suspicion on my part that they came into office, they found the public was willing to spend an awful lot of money, and they didn't really have a coherent list of where the money should be spent," Aspin said. "So they kind of scrambled around, took some programs off the shelf and blew the dust off them and asked the services to tell them what they wanted.

"But then the program didn't have as much coherence as it should have, especially in the early days, when they really had the bucks," he said. "So what I'm asking is, what is the evidence that we've improved our capabilities and our position vis-a-vis the Russians?"