In this study, the bioactivity and biocompatibility of new calcium phosphate bone cements (CPC) using Hydroxy-propyl-methyl-Cellulose (HPMC) was evaluated to understand the effect of HPMC on bone-bonding apatite formation and biocompatibility. In vitro bioactivity was investigated by incubating the CPC samples containing different ratios of HPMC (0%, 2% and 4% HPMC) in simulated body fluid (SBF) for 2, 7, 14 and 28 days. The formation of bone like apatite was confirmed on CPC surfaces by SEM and XRD analysis. Higher HPMC content of CPC showed faster apatite deposition in SBF. A high Ca ion dissolution profile was also reported with an increase of pH in all samples in SBF. The apatite formation ability of these CPC samples was found to be dependent on both surface chemistry and immersion time in SBF. The In vitro cytotoxicity test showed that the CPC samples with 4% HPMC were fairly cytocompatible for fibroblast L-929 cells. SEM images showed that MG-63 cells were successfully attached to the CPC samples and well proliferated. (c) 2010 Elsevier B.V. All rights reserved.