The article is devoted to the question of an assessment of impact of anthropogenous activity on live organisms. The research objective is the analysis of pollution of districts of Krasnoyarsk in size of the fluctuating asymmetry of a sheet plate of an elm stocky. Determination of asymmetry of an elm stocky sheet plate and the assessment of stability of development was carried out with the help of V.M. Zakharov's technique. The integrated indicator of the fluctuating asymmetry was counted on five signs for the left and right sides of a leaf: a leaf half’s width, the length of a vein of the second order, the second from the basis, the distance between the bases of the first and second veins of the second order, the distance between the ends of these veins, a corner between the main vein and the second from the leaf basis a vein of the second order. As a result of carrying out researches nature of the fluctuating asymmetry of a leaf of an elm of stocky was studied. Krasnoyarsk is situated in places with various anthropogenous loading, so on a control site (Oktyabrsky district) the integrated indicator of the fluctuating asymmetry had the smallest value - 0,0576. It was established that the high rate of FA (0,0654) and, therefore, low stability of development of an elm stocky were characteristic for the Sverdlovsk district of Krasnoyarsk that allowed to place this site to the fourth class of pollution. In Leninsky district the fluctuating asymmetry of morphological features of leaves of an elm stocky was lower (0,0631), than in Sverdlovsk the area, this site belongs to the third class of pollution. It was revealed that such morphological features of a leaf as length of a vein of the second order, the second from the basis, and distance between the ends of these veins had most sensitively reacted to environmental pollution.