Abstract: Objective: To analyze the stress distribution of short dental implant with different length and diame-ter in the type Ⅳ jaw bone of maxillary posterior area, providing the theoretical basis for the clinical de-sign of short dental implant in the maxillary posterior region. Methods: Three dimensional finite element was used to simulate the stress size and distribution of implant-bone interface in 7 kinds of Bicon im-plants with different diameters and lengths under vertical loading and a 45 degree slope loading。 Results: The effect of implant diameter on bone interface was more significant than that of length, regardless of vertical load or lateral load. Under the lateral load, the von-mises stresses of group 6*6mm was mini-mum. Under the vertical load, the von-mises stresses of group 6*8mm was minimum, the second place was group 6*6mm. There were no significant difference between 5mm diameter implants with different length. Conclusion: The choice of short implant in the type Ⅳ jaw bone of maxillary posterior area: if the bone in good conditions, 6*6mm implant was suggested, if the bone in moderate conditions,5*6mm im-plant was suggested, if the width of bone was not enough, 4.5*8mm implant was suggested.

Key words: short dental implant, three-dimensional finite element analysis, von-mises stress, Type Ⅳ, bone