This paper introduces the Northcote-Trevelyan Report(1854) that insisted on an examination system as a way for appointing Civil Service. It also looks at transitions in appointment of British officials for foreign service after application of the Northcote -Trevelyan Report. However, the main purpose of this paper is to examine the identity of the British Foreign Office as it was.Firstly, research on appointments of senior domestic administrative officials to the British Foreign Office reveals that they were appointed by a recommendation system. Junior officials, on the other hand, were appointed under both the recommendation system and the examination system until the end of the 19th century. Once the examination system became mandatory in the beginning of 20th century, a Board of Selection was added.However, the examination system was poorly managed by the Board of Selection such as a modified recommendation system.Therefore, until the early 20th century, the aristocracy still played important roles in appointing foreign service.Secondly, when examining residents abroad of foreign officials, an appointment way for diplomats was unclean, though junior officials of resident abroad were appointed the same way as domestic junior officials. In this paper, there was examined the appointment way through analyzing the social and educational origin of diplomats. It was founded that residents abroad of foreign officials were also under aristocracy until the early 20th century. As a result, it was clearly proved that the British Foreign Office’s identity of 1865-1911 was ‘the institution operating by Aristocracy.’