The purpose of this study was to analyze the stress pattern in different bone densities surrounding fin-type implant fixtures under the vertical and inclined loads ($30^{circ}) of 200N. Von-Mises stress, the pricipal stress, and the displacement on the implant fixtures under the loads were calculated by using the finite element method. Four different types of bicon implant fixture were used for this study. The geometries of implant fixtures to develop the model were used by a sales brochure and profile project. Three-dimensional finite element model of the mandible was developed with 6.0 mm implant in diameter wurrounded by approximately 2.5 mm of bone. Bone densities were classified according to the elastic modulus of the tree. The finite element program MSC PATRAN (MSC, Software Corp., USA) were used for analysis of stress distribution. The value of the Von-Mises stress, the pricipal stress, and the displacement on the implant fixtures under the vertical and inclined loads were decreased when the diameter of implant fixture was increased, and increased when the elastic modulus was decreased. The stress on implant fixture under the vertical and inclined loads was distributed through the length of implant fixtures in D3 and D4. The distribution of stress was influenced by the direction of loads. In the wide diameter of implants, the stress was developed at outer surface of bone. In conclusion, this study suggest that stress developing on the peri-implant tissues might be influenced by the dimension of implant, elastic modulus of bone, and direction of loads.