An electromagnetic thermotherapeutic system is adapted to treat a biological tissue and includes an electromagnetic thermotherapeutic apparatus and a high frequency induction heating circuit unit. The apparatus includes a needle assembly and a temperature monitor. The needle assembly is adapted to be inserted in the biological tissue and includes a flexible and bendable needle seat and a plurality of ferrous needles attached to the needle seat and having needle tips extending in a direction away from the needle seat. The temperature monitor is connected to the needle assembly. The high frequency induction heating circuit unit has an induction coil capable of producing an electromagnetic field to induce currents in the ferrous needles and to thereby heat the ferrous needles.