港鐵公司
Though the Daxing Line is classified as a distinct line, the Beijing MTR Corporation Limited operates through-train service on Lines 4 and Daxing, making the two lines effectively one line for travelers. With the opening of the Daxing Line on 30 December 2010, the Beijing MTR Corporation Limited now runs two types of train service on the combined Line 4-Daxing Line route: