दीचू (地区 pinyin: dìqū) are governed by administrative offices (行政公署 xíngzhènggōngshǔ), led by a head of office (行政首长 xíngzhèngshǒuzhǎng) appointed by the province.
Prefecture is developed from the Circuit, which was a level between the province level and the county level in Qing dynasty. In 1928, the government of the Republic of China abolished the circuit level and the province administrated county directly. Soon, this reform was found unfeasible because some provinces had hundreds of counties. Consequently, province was subdivided into several prefectures and regional administrative offices were set up.
At one point, prefectures were the most common type of prefecture-level division. Today they have been mostly converted into prefecture-level cities, and the trend is still ongoing.
There are 17 prefectures remaining in mainland China, mostly in Xinjiang and Tibet.