As an alternative for polymethyl methacrylate, poly (propylene fumarate) (PPF) has been considered as injectable and biodegradable bone cement; therefore, its mechanical and degradation properties are particularly important. As an environmentally friendly PPF-based copolymer, which is reinforced by hydroxyapatite, was studied for the properties of the composite. The composites were investigated by evaluating their mechanical properties, hydrophilicity, in vitro degradability, and cytocompatibility. Furthermore, via applying MC3T3-E1 cells, their cell interaction, including adhesion, proliferation, and in vitro cytotoxicity assay, were assessed. The composite reinforced with 3 wt% hydroxyapatite showed a higher lap-shear strength (0.71 MPa) and bonding strength (5.24 MPa), a maximum compression strength at fracture (92.44 MPa), and compression strength at yield (35.44 MPa), respectively. Also, mechanical strength, hydrophilicity, and in vitro degradation of composites were enhanced in the presence of hydroxyapatite. In this condition, after a period of immersion (52 weeks) in PBS, the weight loss and degradation rate of composites were found to increased. Cell culture tests indicated that the composite was nontoxic and meaningfully facilitated cell attachment and proliferation. Accordingly, controllable strength and degradation of the composite, along with its proven biocompatibility, make the composite a candidate for the treatment of comminuted fractures.