Simple Summary: Breeding biology stands as the paramount component within avian life history. In this study, for the first time, we provided detailed information on the breeding biology of the Indian Blue Robin (Larvivora brunnea), a little-known forest understory bird, for which the breeding biology has been largely unknown. We conducted our fieldwork in northwestern Yunnan, China, in May of 2021. Both parent birds were observed to participate in the breeding process, but the female participated in incubation only. This study highlights how a small single-parent bird adapts its incubation behavior, as well as how parent birds coordinate their breeding to adjust to the cold and unpredictable environmental conditions in high-altitude regions. Breeding biology lies at the core of life history research on birds, and it provides important information for avian conservation. We discovered one nest of the Indian Blue Robin (Larvivora brunnea) on 28 May 2021, at the Laojun mountains in Lijiang, northwestern Yunnan, China. Field observation was combined with the use of a GoPro camera for video shooting to quantitatively study the incubation and brooding behavior. We also conducted measurements of the eggs and nestlings on site and inspected the nesting materials used. A bowl-shaped nest with four eggs was located at 2830 m in the evergreen deciduous broad-leaved forest. All eggs were successfully incubated and two nestlings fledged on 22 June 2021, resulting in a total breeding success of 50%. Only the female bird incubated the eggs and brooded the nestlings. The incubation period was at least 13 days and the nestling period was 13 days. As incubation progressed, the incubation bout duration decreased. During the incubation period, the nesting time of the female bird shows a declining trend as incubation progresses. Both parents participated in feeding the nestling, and the frequency of parental supply increased with the maturity of the nestling. [ABSTRACT FROM AUTHOR]