Cell adhesion is used as a parameter to evaluate the biocompatibility of dental implant and also affected by the surface form of dental implant. Most study have showed different cell reaction by the composition and the surface morphology of implant. Therefore it is thought that the osteoblastic activity would be affected by the surface roughness and composition of implants. This study was performed to evaluate the biological activity and morphological change of normal human osteoblastic cells(NHost) depending on the variations of implant surfaces. We used grade 2 titanium disks which were being air-blasted with TiO2 50 ㎛, 110 ㎛, 250 ㎛ powder by 3psi compressed air and non-blasted as control. We evaluated and compared morphologic change, adhesion assay, and Ca, P, ALP concentration of NHost in vitro. The obtained results were as follows. 1. In the growth curve, although the growth of experimental groups were lower than that of the group of NHost only, there was no significant difference between each groups. 2. Inverted microscopic findings showed NHosts in early stage of each group were adherant perpendicular to the titanium disk and the multilayered NHosts were attached with various directions after 4 weeks. 3. Scanning electron microscopic(SEM) features showed that NHosts in all groups seemed to be attached multilayered and connected with each process after 2 weeks. 4. NHosts' processes were found by the SEM after one day culture. The cell adhesion of experiment group was higher than that of control group. 110 ㎛(the 3rd group) showed prominant process of NHost on the titanium disk surface. 5. Although the concentrations of Ca, P and ALP were gradually reduced, ANOVA analysis of each groups were partially different, and ANOVA analysis of 4th group were significantly different with others. From the aboving results, NHosts cultured on the titanium disks showed similar morphological change and cell proliferation. There were partially differences in each group except the 4th group, and the 4th group were significantly different with other's in biological activity. We thought that biological activity and adhesion of NHost cell on titanium had been affected by the variation of the titanium surface roughness.