The present invention provides a quantization control system for video coding, for optimizing bit allocation based on visual priority which expresses at high precision human visual characteristics for videos, thereby improving subjective image quality of the whole image even with a limited number of bits. An object is extracted from a picture of an input image (S1) and a gaze parameter V(j) for the extracted object is calculated (S2). Then, a texture attribute parameter t(k) of each macroblock included in the object is calculated (S3). The gaze parameter V(j) and texture attribute parameter t(k) are used to calculate a visual priority parameter w(k) for each macroblock. Based on this parameter w(k), a quantization parameter is determined.