It was erected as an apostolic vicariate on 2 August 1929, comprising 10 civil sub-prefectures of the Chungking mission (v.) and entrusted to the Chinese secular clergy. On 11 April 1946, with the establishment of the episcopal hierarchy in China, it was raised to the status of a suffragan diocese of Chungking.
It covers an area of approximately 20,000 sq km. As of 30 June 1947, out of a total population of about 5,000,000, there were 21,393 Catholics; 43 priests; 13 major seminarians and 67 minor seminarians; 14 sisters, of whom 7 were foreign. Among its institutions were 3 orphanages, 2 dispensaries, and 113 schools with 2,930 pupils.
The history of the evangelization of the W. mission is the same as that Chungking (v.); at the time of its erection (1929), 22,960 Christians were transferred to W.