Abstract: A method and a system for identifying a prank call, a client, a server, and a storage medium, and the method includes: sending a questionable telephone number to a server through a network instant message by a client; receiving a query result on the questionable telephone number from the server; adding the questionable telephone number to a contact blacklist when the query result shows that the questionable telephone number is a malicious telephone number; and identifying whether an incoming call from the questionable telephone number is a prank call according to the contact blacklist when an incoming call from the questionable telephone number is received. The present disclosure allows for effective identification of prank calls.