The prevailing sequences in the massive genome sequences, which do not code for proteins or RNAs, have been named junk DNA. It is unreasonable for organisms，in which there is the principle of maximum economy，to accumulate nonfunctional garbage in vital living cells during their long-term evolution. Recent researches have demonstrated that so-called junk DNA possesses important functions and it is believed that more and more junk DNA will be proved to be not garbage but the treasures of the genome.