Abstract: To understand the light requirement characteristics of 'Tianjing3', expand its cultivation range, and improve the spatial utilization efficiency of forest land, four treatments—unshaded control (CK), light shading (LS), moderate shading (MS), and severe shading (SS)—were applied to measure its growth and physiological indicators. The results showed that light shading promoted the height growth of 'Tianjing3' while having minimal impact on its ground diameter, total chlorophyll, chlorophyll a, chlorophyll b, and carotenoid content. It also facilitated the accumulation of soluble sugars and proteins, mitigated the accumulation of MDA, enhanced POD activity, and reduced the stress responses of SOD and CAT. In contrast, moderate and severe shading significantly hindered the height and ground diameter growth of 'Tianjing3', decreased the total chlorophyll, chlorophyll a, chlorophyll b content, and the chlorophyll a/b ratio. These findings indicate that the optimal shading intensity for 'Tianjing 3' is light shading (light transmittance of 80±5%), allowing it to be interplanted in sparse forests and orchard rows with corresponding shading rates in practical applications.