this study explored the effects of changes climate on the growth rate of black spruce in western canadian boreal forests over a 55-year time from 1950 to 2005. a multiple linear regression model was run for tree ring data, mean annual temperature, and precipitation from three sites at different latitudes including the northwest territories, norther yukon, and central saskatchewan. correlations between temperature and black spruce in high latitudes were the lowest, while those in middle latitudes were the highest. the effect of precipitation on black spruce was not significant in western canadian boreal forests. climate change was found to negatively affect the growth of black spruce, possibly due to its intolerance to drought, resource competition, and temperature stress. in the future, the number and size of black spruce in forests of western canada are expected to continue to decline if climate change trends continue.