Description: During the period 2009-2010 a phytosanitary evaluation of 17 breeds of sorghum from breeding experiment of Agricultural Institute - Shumen, grown at different density, has taken place. The development of bacterial diseases - bacterial leaf streak and bacterial leaf stripe, fungal leaf blight and non-infectious chlorosis have been reported. Regardless of plant density, the fungal leaf blight develops strongest (from 16 percentage to 34 percentage), with a tendency of increasing in dense sowing. Regarding bacterial leaf streak, the selection materials have shown mediocre resistance with maximum intensity 38 percentage for thin sowing and 36 percentage for dense sowing. The non-infectious chlorosis occurs depending on origin with disease development from 0 to 48 percentage