Predatory mites in the Family of Phytoseiidae (Acari) are important components in mite biological control. Until now, a native predatory mite, Amblyseius womersleyi has been a subject of intensive studies for implementation of spider mite biological control in fruit orchards, while imported Phytoseiulus persimilis has been successfully implemented in greenhouse environments since 2002. Because of some ecological constraints of A. womersleyi as well as the field environments, spider mite biological control by A. womersleyi has not been successfully implemented. Therefore, demands for another feasible mite predator have increased. This paper reports a newly found predatory mite, Amblyseius californicus, known also as Neosiulus californicus from Jeju citrus orchards. This is the first record of field occurrence of this species in Korea. Some ecological characteristics of this species useful for biological control are also discussed.