The article sununarizes research findings on the tree-ring characteristics of Po Mu (Fokienia hodginsii). Analyzing of the effects of climate change and the intensity of solar activity (sun spots) to annual tree-ring, as a basis for ecological zoning for conservation and planting Po Mu in Vietnam. Wooden cutting samples and meteorological data were collected at Phu Yen district, Son La province. Research results showed that The sampling tree is 240 years old, annual tree-ring width fluctuates over time with cycles ranging from 9 years to 14 years. Most climate indicators affect the growth of Po Mu, the strongest influence is the moisture index from May to October (r = 0.5). The intensity of solar activity is closely relating to similarity index of H21/33 (r = 0.51). Based on the results obtained, the authors has classified suitable ecological zones for developing Po Mu in Vietnam according to three criteria: the topography, rainfall and moisture index.