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The <i>Soybean yellow shoot virus</i> (SYSV) was first detected in Lavras – MG- Brazil in 1984, infecting soybean plants in experimental field. The preliminary studies using electron microscopy, mechanical inoculation in host plants and serology showed that it was a <i>Potyvirus</i> member, able to induce more severe symptoms and different from any other virus already described for soybean plants. Since then, the molecular characteristics of this virus remained unknown. In this work the 3’ end region of SYSV genome, including the poly A tail, 3’UTR, coat protein and part of the NIb and CI regions, was sequenced and analyzed. This region was amplified by RT-PCR, using the RNA extracted from partially purified virions and universal primers, designed to amplify the regions of CI, NIb and CP genes. The nucleotide and amino acid sequences of CI region revealed that SYSV is a distinct member of the <i>Potyvirus</i> genus, with an identity and similarity ranging from 51 to 63% and from 44 to 47%, respectively, when compared to other potyviruses from GenBank. The same was observed for the sequence of the 3’ end region, which presented nucleotide identity between 55 and 59% and amino acids similarity between 29 and 32%. The highest amino acid similarity (61%) was seen with the partial sequence of NIb gene of <i>Glycine virus Y</i>, which only occurs in Australia. The results showed the uniqueness of SYSV, indicating that it is a <i>Potyvirus</i> species not yet described in Brazil and worldwide. <p><p>Keywords: Virus-Viroid, Cereals-Grains, Soybean