At the present stage of the development of education of persons with disabilities ways of enhancing the effectiveness of training students with intellectual disabilities undergo active research. One means of improving the efficiency and further upgrading of teaching methods is information technology. The article gives an example of improvement of methodology of teaching natural science through such information technologies as 3D-graphics. The authors assume that including animated 3D graphics in the computer educational technology, increases the level of assimilation of material by students with intellectual disabilities. The authors have developed lecture notes using the designed computer program and test tasks for the Biology course, examples of which are presented in the article. Statistical analysis of the results of testing students after the lesson and of deferred testing in 9 topics of the Biology course allowed to establish that the learning material is assimilated more intensely by students with intellectual disabilities when using 3D graphics in the learning process rather than without using it.