A modified coxsackievirus showing improved safety and/or aggressiveness to be used for oncolytic virotherapy is provided. A modified coxsackievirus showing tissue-specific suppression of proliferation and comprising a imitated genome consisting of the genome of coxsackievirus B3 wild-type (CVB3-WT) inserted with at least one polynucleotide consisting of a target sequence of tissue-specific microR NA (miRNA) is provided. The mutated genome is preferably further inserted with the region encoding GM-CSF in an expressible form.
