In order to improve the avocado quality, extend its harvest season, and prevent the attack of Phytophthora cinnamomi, elite scion varieties and root rot resistant stocks were introduced to CAES from America or Taiwan avocado producing areas. With the hope for selecting eluit scion varieties and root rot rootstock, outbreeding, inbreeding and seedling selection methods were used.‘CAES 3’ was found to be a better middle-season variety, while‘Hall’and‘Reed’ were found to be better late season varieties. Enough seedlings could not obtained by using the outbreeding and inbreeding methods. By using seedling selection, an eluit variety ’84-O24G’ which tastes better and had the attribute of high resistant to anthracose was found, and after further test it could be a promising variety in future.