There were three Kinds of avoidance System in the imperil examinations during the early Qing period. Firstly, an official from his native province should avoid the triennial examinations held in this province for the title of juren, such as if he was from an area 300 li to a neighboring province, he should avoid the triennial examinations held in the neighboring province. If an offical from Anhui (or Jiangsu) working in Jiangsu (or Anhui) was a magistrate of a prefecture or over this position, and his subordinate was in charge of this kind of examinations or went over the test papers of Jiangnan, his offspring and his clan should avoid the examination which should be acted accordingly to the officials from Shanxi or Gansu. In the examination of Shuntian, the examiners from southern provinces should all avoid the test papers of the candiates from the south, and the officials from other areas should indiscriminately imitate this. Secondly, if someone had relationship by blood or marriage with an examiner, he should avoid this examination. Thirdly, the officials who were in charge of going over examination papers and enrollment and the officials who were in charge of the affairs of the examination hall should avoid each other. The system varied between Yongzheng and Qianlong about whether the examiners' sons should avoid this examination. Although this challenge system had loopholes difficult to control and impassable historical limitations, it had extremely reduced the malpractices in imperial examinations. This was further perfection and development of the feudal imperial examinations.