<p>Arrow bamboo, a typical dominent species in the understory shrub layer of forest ecosystems, plays a crucial role in maintaining the stability of forest ecosystems. The species’ life history and population dynamics are influenced by ramet age, which is a biological characteristic that is difficult to determine accurately. This research focused on <i>Fargesia nitida</i>, a dominant species in the understory of the Minshan Mountain system in southwestern China. In 2009, six fixed quadrats were established in the Jiuzhaigou National Nature Reserve in Sichuan Province, where new shoots were tagged and monitored from 2009 to 2012. Various morphological characteristics of the arrow bamboo, such as basal diameter, height, number of segments, branches, leaves, and stem color, were tracked until 2022 to analyze their changes with ramet age, summarize its growth patterns and screen the morphological indicators that can be used to determine the ramet age of <i>Fargesia nitida</i>. The study identified that basal diameter, height, number of segments, and number of branches could be the key indicators in determining the ramet age of <i>Fargesia nitida,</i> while stem color should not be relied upon as the sole criterion for this determination. This research contributes to the field of age determination in clonal plants and provides theoretical support for further studies on the ramet age of <i>Fargesia nitida</i> populations.</p>