Police have searched through the night for a 22 year-old man who vanished from a nature park near Ipswich yesterday.

The man, who has autism, had been walking to a tourist lookout inside the Goolman Conservation Park near Ipswich with two others when it is believed he ran off.

Police were notified of his disappearance about 1.40pm and a search involving police Queensland Fire and Rescue and the State Emergency Service began two hours later.

A helicopter scoured the area about 7.30pm last night while police have continued searching on the ground.

"He still hasn't been located and our major concern is for his welfare," a police spokesman said.