An image coding apparatus configured to code an image into one or more slices each including a plurality of blocks, the image coding apparatus comprising: first coding means for coding blocks included in a first block line of the slice in an order starting from a left-most block, said first block line comprising a plurality of blocks arranged in a horizontal direction; and second coding means for coding blocks included in a second block line of the slice in an order starting from a left-most block, said second block line comprising a plurality of blocks arranged in a horizontal direction, wherein, when entropy coding a first block in the order of coding blocks in the second block line, the second coding means is arranged to refer to statistical information updated by entropy coding of a predetermined block included in the first block line as initial statistical information for the first block in the order of coding blocks in the second block line, the first coding means is arranged to code a quantization parameter of the first block in the order of coding the blocks in the first block line by using a slice quantization parameter that is provided to the slice as an initial value, the second coding means is arranged to code a quantization parameter of the first block in the order of coding the blocks in the second block line by using the slice quantization parameter that is used by the first coding means when coding the quantization parameter of the first block in the first block line, and quantization parameters of subsequent blocks of the first block in the first block line and quantization parameters of subsequent blocks of the first block in the second block line are coded by using the quantization parameter of a preceding block in the respective block line according to the order of coding. first coding means for coding blocks included in a first block line of the slice in an order starting from a left-most block, said first block line comprising a plurality of blocks arranged in a horizontal direction; and second coding means for coding blocks included in a second block line of the slice in an order starting from a left-most block, said second block line comprising a plurality of blocks arranged in a horizontal direction, wherein, when entropy coding a first block in the order of coding blocks in the second block line, the second coding means is arranged to refer to statistical information updated by entropy coding of a predetermined block included in the first block line as initial statistical information for the first block in the order of coding blocks in the second block line, the first coding means is arranged to code a quantization parameter of the first block in the order of coding the blocks in the first block line by using a slice quantization parameter that is provided to the slice as an initial value, the second coding means is arranged to code a quantization parameter of the first block in the order of coding the blocks in the second block line by using the slice quantization parameter that is used by the first coding means when coding the quantization parameter of the first block in the first block line, and quantization parameters of subsequent blocks of the first block in the first block line and quantization parameters of subsequent blocks of the first block in the second block line are coded by using the quantization parameter of a preceding block in the respective block line according to the order of coding.