City officials meeting here today jumped onto the infrastructure bandwagon by trying to hitch a strong jobs program to President Reagan's plan for imposing an additional 5-cent tax on gasoline to help rebuild crumbling roads and bridges.

On the eve of the opening of their annual convention, leaders of the National League of Cities said they would lobby hard to ensure that at least 1 cent of the gas tax is made available for mass transit, and that the program is used to combat record unemployment.

"There is a logical connection between jobs and filling the potholes," said Seattle Mayor Charles Royer, incoming league president. "We need some link there. We are hurting in terms of unemployment. We are hurting in terms of having the capacity to fix up our physical plant."

Reagan, who is scheduled to address the more than 3,000 city delegates Monday, is expected to make a new pitch for his plan to create "enterprise zones" in 75 distressed neighborhoods. But the mayors here are lukewarm toward the idea, with Royer saying "it's not going to have a major impact" in many cities.

Reagan has maintained that his proposal to repair aging highways and bridges should not be viewed as a public works employment program, although Transportation Secretary Drew Lewis has said it would have the side effect of generating 320,000 jobs, 170,000 of them in the depressed construction industry.

Mayor Ferd Harrison of Scotland Neck, N.C., outgoing league president, said Lewis has told him that the gasoline tax proceeds would be used only to build or expand transit systems or to purchase equipment, not to help cities operate deficit-ridden subway and bus lines. The league plans to push for agreement to allow use of the gas tax money to help replace federal operating subsidies for mass transit, which have been sharply reduced. Royer said the money would help older cities shift some of their capital funds into maintenance operation.

This weekend the league named Los Angeles Mayor Tom Bradley to head a special task force to help tailor the infrastructure proposal to suit the cities' needs.

The city officials also served notice that they intend to lobby Congress to increase general revenue sharing, which Royer called "mother's milk for cities." Harrison said the $4.6 billion in no-strings aid, which has not been increased since 1976, is far more effective than many specific grant programs.

Reagan also is expected Monday to seek support for his New Federalism plan to turn over dozens of domestic programs to the states, and also to suggest that cities cannot continue to look to Washington to solve all their problems. But Harrison said that the New Federalism "is not acceptable" unless the White House adopts a long list of changes, such as providing supplemental federal aid to the poorest states.

Royer, in an interview, said local businesses in Seattle had raised $2 million to offset federal budget cuts, but had made up only a fraction of his city's $30 million gap. "It's not realistic to expect the private sector to step in and replace basic programs," he said.

Fewer businesses are hawking their wares at convention exhibits, and the league has cut its own staff from 135 to 50 since last year. With municipal tax revenues still depressed because of the lingering recession, city officials are in no mood for more federal cutbacks.

"We at the local level our doing much better than our colleagues at the national level at living within our means," said New York City Council President Carol Bellamy. "Washington is only talking about fiscal austerity but the cities are living it."