Abstract: To simplify the on-site construction procedure of steel reinforced concrete (SRC) beams, this paper combined the advantages of pre-stressing technique and prefabricated structures, and then presented a novel partially precast prestressed steel reinforced concrete beams. Based on the test results of 5 flexure-dominant beams and 5 shear-dominant beams, the effects of pre-stressing timing, pre-stress ratio, pre-stress location, and the type of precast concrete on failure pattern and strain distribution were investigated. Meanwhile, the crack propagation, load-carrying capacity and deformation development of PPPSRC beams were thoroughly explored. The test results indicate that the pre-stressing timing has a limited effect on the mechanical behavior of PPPSRC beams because the cracking load difference and the peak load difference of different pre-stressing timings were both within 5%. The pre-stress ratio and location strongly affect the anti-cracking capacity of PPPSRC beams. The cracking load can be increased by 166% and 33% when higher pre-stress ratio and UHPC are applied, respectively. Equations for predicting the flexural strengths, shear strengths and cracking loads of PPPSRC beams were put forward, and the calculated values are in good agreement with the test results.