Abstract: To investigate the cellular compatibility of β-calcium metaphosphate (β-CMP)/poly-L-lactide (PLLA) fracture innerfixation composites prepared by a two-step method，and to provide a biological evidence for the application of the composites，the osteoblasts proliferation and adhesion on β-CMP/PLLA composite were analyzedby methyl thiazolyl tetrazolium (MTT) and SEM，respectively. The cytology experiments show that β-CMP/PLLAcomposite can promote cells growth and osteoblasts adhered and spread well on the materials. The new fracture innerfixation material，β-CMP/PLLA composite，has good cytocompatibility in vitro.