Video signal coding apparatus includes a quantization unit which quantizes a luminance signal of each of a first picture and a second picture coded after the first picture, and quantizes a chrominance signal of each of the first picture and the second picture. A code amount obtainment unit obtains a luminance code amount and a chrominance code amount of each of the first picture and the second picture; and a rate calculation unit calculates a rate of the chrominance code amount with respect to the luminance code amount for each of the first picture and the second picture. A rate control unit changes a coefficient value of at least one of the first matrix and the second matrix used in quantizing the second picture, before the quantization unit quantizes the second picture, so that the rate for the second picture becomes smaller than the rate for the first picture.