WASHINGTON (AP) _ People looking to snag one of the 50,000 to 60,000 jobs rebuilding the nation's cities under President Clinton's economic plan should be prepared to work for a short time, maybe for low pay.

Clinton's plan sets aside $2.5 billion in community development block grants, handed out by the Department of Housing and Urban Development. The money is to be used for public works projects tabled by cash-poor local governments.

Those projects, according to Clinton's plan, would make enough work to give people a little extra spending money and boost the economy. It's up to the cities to decide which projects to spend the grant money on.

The mayors of 470 cities came up with 107,083 eligible projects, worth $3.5 billion. They say these projects could start within 120 days and be completed by December. Most of the projects would need small crews, mainly 25 people or fewer to work for about one month, the mayors say.

Many of these projects involve paving roads, rebuilding sidewalks and bus stops, sprucing up recreation centers and playgrounds - things that many cities could use public works employees to do.

Michael Nail, who monitors community development issues for the National Association of Housing and Redevelopment Officials in Washington, said the plan could mislead some people into thinking that there will be a large number of full-time positions available.

''That's always the problem when you talk about job creation,'' Nail said. ''They could be low- to moderate-income jobs, service workers. The monies could be used to support existing staff. Still, regardless of the types of jobs, there will be a ripple effect on the economy.''

Housing Secretary Henry Cisneros said he wants to make sure that the cities use the money for new jobs, rather than other needs.

''There's been some suggestion that our regional offices might play a greater oversight role in making sure that the projects are jobs-oriented,'' he told reporters in a briefing last week.

York, Pa., Mayor William Althaus, president of the U.S. Conference of Mayors, said local leaders are committed to creating jobs, as Clinton wants.

''I personally assured the president in our meeting a week or two ago that we understood ... that a responsibility had been given to us to deliver important projects and deliver jobs, and that we would meet that commitment,'' Althaus said.

Rep. Charles Rangel, D-N.Y., who represents an inner-city district, said he'll be watching to see whether the block grants are spent as promised. He cited how, during President Lyndon Johnson's administration, some cities spent job training grant monies on city employees.

''We've had this problem before. But it's not going to happen this time,'' Rangel said. ''They're going to have to show that they'll hire new people. It was made abundantly clear that we're talking about new jobs, and not just subsidizing old ones.''

HUD currently funnels about $4 billion in community development money to cities. Under Clinton's plan, cities would get an extra 60 percent.

So, a city that gets $15 million in community development block grants would get approximately $9 million more. The grants can start going out as soon as Congress approves Clinton's plan.