A pseudorabies virus (PRV) or a modified form thereof, or a genome sequence or a cDNA sequence containing the PRV or the modified form thereof, or nucleic acid molecules of a complementary sequence of the cDNA sequence, for treating tumors of subjects and/or reducing or inhibiting tumor recurrence, and for preparation of a pharmaceutical composition used for treating the tumors of the subjects and/or reducing or inhibiting the tumor recurrence. A method for treating tumors and/or reducing or inhibiting tumor recurrence, comprising a step of administering, on a subject having a need, the PRV or the modified form thereof, or nucleic acid molecules of the genome sequence containing the PRV or the modified form thereof.