A decompression circuit for decompressing data includes a first decompression unit and a second decompression unit. The data sequentially includes a compressed first string, a compressed distance-length pair and a compressed second string. The first decompression unit performs a first decompression on the data to obtain a first string, a distance-length pair and a second string. The second decompression unit receives and decompresses the first string, the distance-length pair and the second string. The first decompression unit does not involve data associated with the distance-length pair when decompression the second string.