An ultrasonic diagnostic device and ultrasonic three-dimensional image generation method generate a three-dimensional image by expressing interaction by dispersion, absorption, or the like of light in tissue or between tissues. The ultrasonic diagnostic device displays a three-dimensional image of a target object based on at least one piece of volume data among luminance volume data, blood flow volume data, and elasticity volume data. The ultrasonic diagnostic device includes: a light source setting unit to set light source data indicating characteristics of a light source set in a three-dimensional space； an optical characteristic setting unit to set characteristics of the volume data related to the light source； an illumination calculation unit calculates illumination of coordinates of the volume data based on the light source data and optical characteristics and generate illumination volume data based on calculated illumination； and a projection processing unit generates the three-dimensional image from the illumination volume data.
