Grapevine fanleaf Virus (GFLV) is one of the most devastative viral diseases of grapevine in worldwide. The infected vines show leaf malformation, vein banding, yellow mosaic and reduction in quality and quantity of grape. GFLV has widespread distribution in Iranian vineyards with high level of genetic diversity, however, but only sequence of RNA2 segment of the genome for Iranian isolates are available. In order to determine the complete nucleotides sequence of RNA1 of Iranian isolates of GFLV, small RNAs were extracted from infected grapevine, then the miRNA library was constructed and sequenced in the Illumina-Highseq2500 platform. Adaptors sequence and low quality reads were discarded from the raw data. The filtrated reads were aligned using Bowtie2 in the Ugene package. Phylogenetic analysis was carried out using MEGA-X package. Of the 436874 refined reads, complete sequence of RNA1 of four isolates of GFLV were obtained after alignment. The RNA1 of these isolates had 7302-7330 nucleotides length. The pairwise sequence identity of polyprotein 1 among Iranian isolates and those deposited in the GenBank ranged from 82-88% at the nucleotide level and from 85-93% at the amino acid level. The sequence identity of the polyprotein 1 among Iranian GFLV isolates ranged from 79-83% at the nucleotide level and from 80-87% at the amino acid level. This results indicate that sequence diversity of polyprotein 1 in Iranian GFLV isolated is comparable to the global diversity. In the polyprotein1, NTP Banding protein with 90% of homology was the most identical and Protease cofactor protein with 63% of homology had the least similarity with the proteins of polyprotein1 reported for the other GFLV isolates. In the phylogenetic tree, isolate Iran1 and an isolate reported from China, was put in a divergent clade, but other Iranian isolates clustered with isolates of other counterparts in a same group.