While Lebbe was a seminary student in 1900, the Boxer Rebellion occurred in China, and the Belgian missionary Ferdinand Hamer was martyred in Inner Mongolia.
He was ordained in Beijing on 28 October 1901, and was then sent to do mission work in Xiaohan village of Wuqing County (now part of Tianjin Municipality) and elsewhere in the Beijing-Tianjin region.
Lebbe continued to lobby the Vatican to reform the China mission, even meeting with the Pope to make his case, and he was influential in the appointment of the first six Chinese bishops, whose consecration he attended, on 28 October 1926 in St. Peter's Basilica.
The six were Zhu Kaimin in Haimen (朱开敏,海门教区), Cheng Hede in Puqi (成和德, 蒲圻教区), Chen Guodi in Fenyang (陈国砥,汾阳教区), Zhao Huaiyi in Xuanhua (赵怀义, 宣化教区), Hu Ruoshan in Taizhou (胡若山, 台州教区), and Sun Dezhen in Anguo (孙德桢, 安国教区).
[3] In 1927, Lebbe's applied for and was granted Chinese citizenship and returned to China in 1928, aiding Bishop Sun Dezhen in Anguo, Hebei and helping establish two Chinese religious orders, the Little Brothers of St. John the Baptist (Les Petits frères de Saint-Jean-Baptiste, 耀汉小兄弟会) and the Little Sisters of St. Theresa of the Holy Child (Les Petites soeurs de Sainte-Thérèse-de-l'Enfant-Jésus, 德来小姊妹会), the latter named for Saint Thérèse of Lisieux).
Treated as a Kuomintang spy, Lebbe endured six weeks of brainwashing and physical mistreatment, and was seriously ill when released more than 40 days later.
Lebbe was instrumental in promoting the inculturation of the Catholic Church in China, a movement which was only partially underway when the new Communist regime expelled all foreign missionaries after 1949.
Many schools and institutions bear his name, and he received official praise from the ROC government after his death, including a memorial tablet at the National Revolutionary Martyrs' Shrine in Taipei.