A safety syringe includes: a hollow needle normally held in a front portion of a syringe, a plunger slidably held in the syringe for injection use, a coupling member retained in the plunger engageable with at least a biasing socket recessed in a rear needle portion of the hollow needle with the biasing socket generally formed as a conical shape having a longitudinal conical axis inclined from a needle axis of the needle when normally fixed in the syringe with the needle axis aligned with a syringe axis longitudinally formed in a center line of the syringe, whereby upon retraction of the plunger and the needle coupled to the plunger, with the biasing socket of the needle forcibly coupled with the coupling member, into a bore portion in the syringe, the needle will be automatically inclined as the biasing socket of the needle is restored by the coupling member retained in the plunger to prevent an outward protruding of the retracted needle from the syringe for preventing its pricking to the others.