Provided is a use of tobacco gene NtTCTP for resisting potato virus Y in plants (PVY). The tobacco gene has a full length of 507 bp and encodes a protein containing 168 amino acids, the activity of which is closely related to the PVY-resistance of tobacco. When the gene is silenced in tobacco, tobacco shows stronger resistance to PVY and can reach immune levels; and when the gene is overexpressed in the tobacco; and tobacco becomes more sensitive to PVY The gene can be used in the breeding of PVY-resistant plants such as tobacco.