Serum immersion, a new method of pre-treated HA ceramics, has been compared with SBF immersion and untreated HA particles in cell culture condition. MTT assay indicates that serum-immersion lessens particles cytotoxity of HA particles in cultured L929 mouse fibroblast cell (p<0.05). Neither immersion nor traditional physical factors such as particle size, shape should be responsible for these because SBF immersion with the similar factors results in no significant improvement. The reason might be serum proteins adsorption and biommetic microstructure formation on the ceramics surface, which affect cellular membrane behaviors, phagosome metabolization and cellular protein secretion. Otherwise, cells with particles degraded early apparently, which indicated that particles influence the cell cycle. The whole processes must be correlated intensively with cytokine, protease and intracellular ion concentration, which would be discussed in our follow-up studies.