Beleaguered taxpayers in this traditionally liberal state, caustically dubbed "Taxachusetts," will get a break from escalating property taxes in the form of a state-mandated cap on local spending.

Gov. Edward J. King, a conservative Democrat who campaigned last year on a tax-cutting measure similar to California's Proposition 13, signed into law today a bill imposing a 4 percent per year ceiling on local property tax increases. The limitation is the first such in Massachusetts history.

In a speech carried on television and radio this afternoon, King claimed victory despite his failure to persuade the legislature to approve his "zero percent tax cap" proposal, which would have frozen all local spending at last year's levels.

"We have changed the way elected officials think about government spending of taxpayers' money," said King. "Stopping the runaway express train of local government spending is no small matter."

Massachusetts has the second highest property taxes in the nation-Alaska's are highest-with recent local tax increases of 8 to 12 percent annually.

King has promised business leaders a better financial climate, contending stiff tax bills have contributed to the exodus of industry to cheaper pastures.

Playing to the increasing bitterness of the state's taxpayers, King won an upset victory over liberal Gov. Michael S. Dukakis last November, in part because of a promise to slash property taxes by $500 million.

The pledge hinged on freezing all increases in local spending, then using state aid and new local revenues to reduce property tax bills.

The state aid would come from trims in the state budget, mostly in the area of social services, and the new local revenue would come from an increased auto excise tax and other sources.

But the mostly Democratic legislature scuttled the plan with its own 4 percent tax cap proposal. "The governor's plan was unworkable," said State Sen. Chester A. Atkins, chairman of the Ways and Means Committee. "Most cities and towns could not afford to do it without drastically reducing services."

Added Dr. William H. Hebert, executive director of the Massachusetts Teachers Association, representing about 55,000 educators: "We were unalterably opposed to the zero cap; it was an ill-conceived campaign promise." The association had charged that King's plan would result in the layoffs of 7,000 teachers.

"In the context of the entire battle on the issue, at least the legislature is being reasonable; we could live with a 4 percent cap," said Hebert.

The governor, angered at the legislature's refusal to toe the administration line, countered early last month with a massive grass-roots campaign using his political organization to collect more than 100,000 signatures on petitions supporting his proposal.

"The voice of the taxpayer is not being listened to," said King, grumbling that the 4 percent ceiling "wipes out any hopes for meaningful property tax cuts this year."

He gave up the fight, sources said, rather than risk an override of his threatened veto of the 4 percent cap.

Today, King promised to submit a new zero cap bill and to appoint a special commission on property tax relief. An he had some halfhearted praise of the legislature's action, though the spending restrictions were not as tight as he wanted.