On the experimental field of the Institute of Lowland Forestry and Environment, the sensitivity of 167 poplar genotypes to fungi Marssonina brunnea and Melampsora spp. was evaluated on the basis of the number of fruiting bodies per cm2 of the leaf surface in the first decade of September from 1997 to 2004, each year. The sensitivity of 86 clones to these pathogens was already evaluated in the previous period (1992-1996), and our results were in accordance with the results reported in the paper by Avramović et al. (1998). With a smaller number of clones a gradual increase in sensitivity was evident, i.e. their transition from the group of lower sensitivity to the group of clones of higher sensitivity to the mentioned fungi. It was also found that the genotypes in the stoolbed nursery (81 clones in total), introduced later, manifested a different degree of sensitivity from the practically insensitive individual clones to those of high sensitivity. These clones, as well, manifested a different sensitivity to the studied fungi respectively having a higher sensitivity to M. brunnea and lower to Melampsora spp. and vice versa. At the same time, it was established that the number of fruiting bodies of one or the other fungus on the leaves of the genotypes was different in particular years depending on the rainfall and temperature during vegetation.