Titanium has lower density and better strength/weight than most steels. Besides, titanium is chemically more stable, it can resist corrosion in many hostile environment. Thus, applications of the titanium in medical uses, such as dental implant, are very common. However, titanium releases ions when it was embedded in human body. In the dental implant application, although the titanium stiffness is close to alveolus bone, it is still six times higher than cortical bone, the strength difference between these two materials is too large. An isolation layer between the titanium implant and the cortical bone will help reduce difference in strength. Based on this concept, the modification of implant surface is an important subject in the application of dental implant. In this study, the finite element method was used to analyze titanium implants, the implant has nano-porous of oxide layer on the surface. Stress distribution on the implants and alveolus bones were investigated. And the results can provide important information for the design of the implant.