The invention relates to application of preparation folikonanozonda, containing Gds folic acid, which may be widely used in medicine. Purpose of the invention - creation of preparation based on synthesis of nanoparticles a GD, contained in silica with folic acid, which is used as kontrastora in magnetic resonance visualization method of cancer cells. Description of the Invention consists in the fact, that while introducing of this complex in matrix, surrounding cancer cells and tumor, contrast is created field, allowing more clearly visualise picture of image of cancer cell and tumor, to estimate their dimensions and shapes. The proposed method is effective for early detection of cancer cells and tumors, their diagnosis in clinical tests. Preparation folikonanozond safe, non-toxic, is stable at room temperature; it allows images tumors from 2000 of cancer cells, is able into a in interaction with cancer cells, shows low cost production.