Education Secretary Terrel H. Bell said today that improvement of public education is shaping up as an important 1984 presidential campaign issue, but he pointedly rejected Democratic demands that his department lead the way in financing the effort.

Addressing the first of a series of nationwide forums in response to last month's report by the National Commission on Excellence in Education, Bell said the administration is convinced that it should play only a modest role in funding academic research and student aid.

"This may cause you to snort with disgust," he told educators at Michigan State University, "but the plain answer is that the state legislatures must levy the taxes and appropriate the money. It's that simple . . . . We ought not start paying teachers' salaries and buying textbooks on the federal level."

Bell said the final 10 percent of President Reagan's income tax cut this July would leave room for the states to raise revenues "so they can fill the void."

Reagan had reacted to the commission's proposal for greater federal leadership in education by calling anew for tuition tax credits, school prayer and abolishing the Education Department.

Former vice president Walter F. Mondale, a Democratic candidate for president, quickly called for an $11 billion program of block grants to schools, research money and aid to disadvantaged students.

Bell today sharply criticized Mondale's proposal, saying that more categorical aid programs would only add to federal red tape.

"I think the states have been doing a bum job, but I don't think the answer is to start federalizing the operation," Bell said.

"The battle lines are being drawn around whether there ought to be massive new amounts of federal money," he said. "One of the largest blocks of votes at the Democratic Convention is the National Education Association. The candidates will have to reach out for those delegates."

Bell said the teaching profession is in "sad shape," and urged the states to select "master teachers" in the public schools and pay them substantially higher salaries. Calling the teachers' unions "a chief obstacle" to altering uniform salary schedules, Bell said, "They must yield to reason on this point."

Judith Lanier, dean of Michigan State's College of Education, said it is difficult to devise methods for more rigorous evaluation of teachers. "Teachers need to be assured that the judges, whoever they are, are accountable in some way," she said.

Lanier also insisted that more federal aid is needed, saying, "I don't think prayer is going to do it."

Republican Gov. Lamar Alexander of Tennessee blamed the teachers' unions for defeating his recent proposal for a master teacher program in his state.

"Not one state system pays one public school teacher one penny more for doing a good job teaching," said Alexander, the son of two teachers. He said teachers "are encouraged toward mediocrity by low wages, lifetime contracts, little real evaluation and not one penny of pay for performance.

"This huge system is increasingly dominated by teachers' unions who are determined to keep things the way they are." Nearly half of Tennessee's teachers leave for another profession after seven years, he said.

But Alexander rejected calls for increased aid from Washington, saying the federal government "now pays about 10 percent of the bill and gives 50 percent of the advice."

Pat Daly, vice president of the American Federation of Teachers, said many school districts have tried and abandoned a master teacher approach. "No one seems to be able to come up with a system that doesn't become a form of cronyism," he said. "It comes down to who knows the evaluators, who plays golf with the superintendent, and who doesn't cause trouble."

Daly also said that federal tax cuts will be offset by a recent state income tax hike in Michigan. "The secretary is just passing the buck back to the states, which are not equipped to deal with the problem," he said. "If I were a teacher giving the administration a grade, it would be D-minus."