At present, it is found that there are over 20 enzymes related to fruit development among which 14 mRNA increase. Eight enzymes can be induced by ethylene. Many ripening-related genes have been cloned,sequenced and located in the chromosomes. The expression of these enzymes can be inhibited by using antisense technology, thus disclosing the function of them in fruit ripening, and inhibiting the senescent process of tomato from molecular level. Seven antisense genes have been transfered to tomato. Antisense fruits keep fresh for 90～120 days in vitro.