A device for automatic translation of patent claims automatically translates a first language claim into a second language claim. The device includes an element noun retrieving module, a complement determining module, an organizing module. and an automatic computer translating module. The element noun retrieving module retrieves an element noun from the first language claim. The complement determining module determines a complement definition from the first language claim, as a combination of an interrelationship definition and object element. The organizing module forms an organized structure by organizing the element noun, interrelationship definition, object element and an organization identifying word. The automatic computer translating module determines a translation sequence of complement definitions in the organized structure according to a defining sequence of all complement definitions in the organized structure or according to an interrelationship definition belonging attribute of each interrelationship definition in the organized structure to obtain a second language claim translation.