The purpose of this study was to estimate influence of lysine for osteogenesis in the porous hydroxyapatite (HA) scaffolds with bone marrow cells. The HA scaffolds were soaked in 100mM concentration of lysine solution. They were kept in bone marrow cell suspension at 1×106 cells/ml density. Another HA scaffolds without immersion in lysine solution were kept in the cell suspension at 1×106 or 1×107 cells/ml density. They were respectively implanted into dorsal subcutis of rats for 4 weeks. Serially sectioned paraffin specimens were made and observed histologically. In several sections, total pores and ones with bone were counted. Many pores containing bone were found in1×107 cells/ml concentration group. The significant difference was between 1×107 cells/ml group, the lysine group, and 1×106 cells/ml group. Although more bone formation was seen in lysine group than in 1×106 cells/ml group. There was no significant difference between the groups. Concentration of lysine to add in culture medium or scaffold should be improved respectively.