The money for the "Put Illinois to Work" program comes from the federal stimulus, but it dries up Sept. 30 unless lawmakers in Washington extend it.
Quinn touted the program at a landscaping company on Chicago's West Side during an event with U.S. Department of Health and Human Services Secretary Kathleen Sebelius.
The program started about two months ago. It gives employers tax credits to create temporary jobs that Illinois officials hope might be made permanent.
Private, public and nonprofit businesses can sign up to hire people through the program. Participants' income must be below 200 percent of the federal poverty level. That's $2,428 per month for a family of two.
Earlier Wednesday Quinn signed a bill requiring 90 percent of the workers performing state funded public works projects must live in the state.