Lychee (Litchi chinensis) ‘Hak Ip’, ‘Yu Her Pau’ and ‘No Mai Tsze’ (73-S-20)’ are the three most important varieties currently used in commercial production of lychee nuts in Taiwan. However, the lychee industry in Taiwan has encountered a severe set back by relying solely upon these three varieties because the ‘Hak Ip’ variety yields a short production period from mid-June to late June, flooding the short market and bringing down the price of lychee nuts. Although growing the early-season variety ‘Yu Her Pau’ and the late late-season variety ‘No Mai Tsze’ may extend the period of supply of lychee, the labor costs for production of ‘Yu Her Pau’ are high and yields of ‘No Mai Tsze’ are low and unstable. A lychee breeding program was initiated in 1982 at TARI to overcome the bottle neck facing the lychee industry in Taiwan. This breeding program has resulted in the release of seven new lychee varieties (‘Tainung’ series) with different production periods. These varieties have resolved problems facing lychee production at different latitudes and altitudes. Thus, the use of these novel varieties has resulted in the extension of lychee production period from the traditional 2 months (from early May to early July) to 5 months (from late March to early August) each year in Taiwan.