The staff of a major Virginia legislative commission said today that the state's share of funding for public schools fell during a recent seven-year period and predicted the legislature is not likely to make up the gap even with Gov. Charles S. Robb's commitment to increased education spending.

The General Assembly will have to spend an additional $228 million during the next two fiscal years to reverse the decline of the past seven years, the Joint Legislative Audit and Review Commission said in a staff report.

A senior legislator said the assembly is not going to be able to find enough money to meet all of the needs, including education, that the report cited.

"It's a dream world," said Democratic Del. Theodore V. (Ted) Morrison Jr., chairman of the House Finance Committee. He said he is concerned that the study did not assess whether the state's hard-pressed local governments have spent their tax dollars efficiently.

The Robb administration has said that it will make increased state funding a major goal of the 1984 General Assembly. George Stoddart, a Robb spokesman, said today he does not know what the total cost of the new education spending proposals will be.

The report said that while actual dollar amounts of state aid to education have increased in recent years, the total has not kept pace with inflation. State funding for the "standards of quality" it has imposed on local school systems fell from 82.4 percent of the mandated costs in 1975 to 78 percent in 1982, the report said.

It also said the percentage of state spending for special education costs dropped from about 28 percent to 21 percent in the same years. Overall state funding for local education fell from 46.3 percent to 43.6 percent, the report said.

State aid to local governments currently totals about $3.2 billion in the state's biennial budget, of which about $2.3 billion goes to education, including local school systems.

State Sen. Hunter B. Andrews, the Senate majority leader and chairman of the commission, said today that he "would not envision any new taxes for 1984," a position that Robb has taken.

George R. Long, executive director of the Virginia Association of Counties, praised the report, saying it "has given us documentation for what we have been asking for for years . . . . The state is exercising the authority but doesn't put up the money."

The joint legislative commission report, part of a year-long effort to assess the impact of state-imposed requirements on local governments, said the percentage of state aid for most major programs "has kept pace with local program costs" while aid for a variety of services has risen significantly.

It said the state would have to increase other aid to localities by an additional $319 million if it wanted to ease tax burdens on the localities. The report said the state is unlikely to fund the gaps and said the assembly "should establish mechanisms for determining costs of mandated programs."

Andrews asked representatives of the governor's office to a hearing on Nov. 14 to discuss the report. State School Supt. John Davis said yesterday that he had not seen the report and declined to comment on its education provisions.

In the JLARC study, 86 percent of the local governments surveyed said state aid for education is inadequate, compared to 78 percent for jail construction and 73 percent that mentioned aid for police departments.

The report did not tackle the perennial issue of state highway funds, an increasingly important issue in Northern Virginia. It noted that much of the discrepancy in per capita aid to rural counties is due to the state's highway allocation formula and said that issue will be addressed in a report to be issued in December.