The objective of this paper is to analyze service reliability of bus rapid transit (BRT) taking Changzhou BRT as an example. Headway irregularity, potential waiting time, equivalent waiting time, and reliability buffer time are recommended to measure service reliability of BRT. Temporal and spatial distributions and comparisons are analyzed. Findings are that passengers of Changzhou BRT need to budget, on average, an extra 3–5 minutes beyond their typical journey time for selected origin-destination pairs to ensure on-time arrival at destinations with 95% probability. Extra time budgeted for bus waiting beyond mean waiting time contributes to more than 80 percent of extra time budgeted for a journey, while only 20 percent is budgeted for in-vehicle travel time. Service reliability is best near a route’s origin terminal and gradually deteriorates along the route, then improves when approaching the route’s end.