A MRI guided high-intensity focused ultrasonic therapeutic system comprises: a MRI apparatus and a high-intensity focused ultrasonic therapeutic apparatus. Said MRI apparatus includes the first treatment bed and said high-intensity focused ultrasonic therapeutic apparatus includes an ultrasound transducer and a moving and positioning means, which drives said transducer to move in respective directions. Wherein, said moving and positioning means is placed outside of the bore of the MRI apparatus during treatment and a supporting rod, which can extend into the bore of the MRI apparatus, is connected to said moving and positioning means at one end and is connected to said ultrasound transducer at the other end. In the system provided by the present invention, said ultrasound transducer can move in multiple orientations, freely move without any limitation of space under the treatment bed, brings less interference to the MRI apparatus, fully exerts the function and efficiency of the MRI apparatus and achieves the best therapeutic effects.