Głowacka, K., Jeżowski, S. and Kaczmarek, Z. 2013. Gas exchange and yield inMiscanthusspecies for three years at two locations in Poland. Can. J. Plant Sci. 93: 627-637. The influence of gas exchange parameters on yields of six Miscanthus clones were evaluated in two locations over three years. Five out of six genotypes had significant increases in the photosynthetic rate and intrinsic water use efficiency between the third and first or third and second years, while intercellular CO₂ concentration and stomatal conductance decreased. In addition, the multiple regression analyses of yields on parameters showed that the type of the correlation coefficients for transpiration, stomatal conductance and intercellular CO₂ concentration varied throughout the years. The strongest correlation (0.86) between yield and photosynthetic rate was found for 3-year-old plants.