To meet the requirements of minimally invasive surgical treatments for osteoporotic vertebral compression fracture, various strategies have been proposed to enhance the properties of calcium phosphate cement (CPC). Here, a new strategy was developed by incorporating poly (γ-glutamic acid) (γ-PGA) and its strontium salt into the formulation of alpha tricalcium phosphate (α-TCP)-based CPC. Effects of γ-PGA on the injectability, cohesion, setting times, mechanical compressive strengths and cytocompatibility were systematically studied. Results showed that the injectability, cohesion and setting times were considerably improved by introducing γ-PGA into the CPC. Moreover, after setting for 7days, the compressive strengths increased from 14.6±1.4MPa for pure CPC to 35.3±1.7MPa for CPC with 8.9wt% γ-PGA and further to 61.2±5.4MPa for CPC with 8.9wt% γ-PGA combined with its strontium salt. In vitro osteoblast proliferation tests showed that the group of CPC modified by γ-PGA and its strontium salt had better cytocompatibility than the pure CPC group. All results suggest that optimal properties were obtained for the cement with 8.9wt% γ-PGA added to its solid phases and using strontium salt as the reactive liquid phase, making it as a promising candidate for application in kyphoplasty.