Police said a man approached the boy, 11, at about 8.20am in Attlee Street, Normanton, yesterday.
He tried to grab the victim’s bag strap as he walked past.
But the boy resisted and the man then ran off.
Detective Inspector Tim Hunt of Wakefield District CID, said: “We are investigating this attempted robbery and would like to speak to anyone who has information or saw what took place.
“It took place during a time of day when there would have been plenty of people around and it is possible someone may have seen the suspect in the Attlee Street area just prior to or after the incident."
The man is described as being in his 50s, white but with tanned skin, about 5ft 8ins tall, and of medium build.
He was wearing a black and grey coat, with a black and grey hood.
Anyone with information is asked to call police on 101, quoting crime number 13180027174.