Abstract: Cucumber is one of the major vegetables in greenhouse production. The management of cucumber production is very complicated and it demands for a large amount of specialized experiences. To meet this demand, and to meliorate the situation of domain expert scarcity as well as to conserve and spread the knowledge and experiences of experts, the Expert System of Cucumber Greenhouse Culture was developed. This Expert System can provide users with cucumber cultural technology under different environmental conditions and in different growth stages, including planting, controlling of diseases and insect pests. The object-oriented Visual Basic Language was used to develop the Expert System.