Larvae of butterflies are among the important pests of sugar beet, the most important of which is sugar beet moth. The larvae of sugar beet moth, Scrobipalpa ocellatella Boyd (Lep.: Gelechiidae), feed on central young leaves, resulting in considerable damages. In addition to direct damage (quantitative and qualitative reduction of sugar beet yield), the pest provides suitable conditions for penetration of pathogens, resulting in wilt and seedling death in the field and the silos. In Iran, the damage caused by them in sugar beet fields is estimated to be between 20% and 25%. This moth is laid out behind the central leaves of sugar beet and the entrance of the larva into the central buds and ultimately the gland reduces the growth and thus reduces the quality and yield of the product. Studies and observations showed that some cultivars and lines suffer less damage. The number of generations and the lack of impacts of pesticides make them more prone to pests in the field. This study was conducted to evaluate the damage of this pest by sampling intact and infected tubers and the damage of pests in terms of reducing root and sugar yield on 24 sugar beet genotypes. The results showed that pest damage was significant on root and sugar yield at 1% level. The lowest and the highest pest damage in terms of yield reduction were 3.83 and 11.52 t / ha, on SBSI029 and IC varieties, respectively. Also, the lowest and highest losses in terms of weight loss were 0.93 and 2.69% on varrity SBSI029 and paternity 007, respectively.