An image encoding device includes: a first encoding unit for calculating a generated code amount when encoding image data using a fixed quantizing parameter, and block distinction regarding whether a macro block is a block for performing temporal prediction or block for performing spatial prediction regarding a picture for predicting a temporal direction; a code amount control unit for setting the offset amount of a quantizing parameter so as to have great code amount to be assigned to a picture including many images to be referenced according to a percentage between the block for temporal prediction, and the block for spatial prediction based on the results of the block distinction, and determining a quantizing parameter based on the generated code amount calculated at the first encoding unit; and a second encoding unit for encoding the image data using the offset quantizing parameter for realizing a target generated code amount.