There existed two systems of envoys, i. e. the central system and local system, of which the former played the leading role and the latter played a supplementary role.

• 从巡行形式上看，此时的遣使巡行一分为二，正式分张为中央和地方两大系统，逐步形成中央系统主导、地方系统辅助和补充的格局。