Abstract: One hundred and six thousand five hundred and ninety unigenes from fruit transcriptome of Rosa roxburghii Tratt were screened using MISA software. A total of 21 711 SSRs that occurred in 18 155 unigenes were identified，and the frequency of these SSRs was 20.37% and mean distance was 1.68 kb in the unigenes. Trinucleotide，tetranucleotide and dinucleotide were major types，accounting for 26.87%，26.77% and 24.93%，respectively. AG/CT，AAG/CTT were respectively most frequent motifs in dinucleotide and trinucleotide repeats，accounting for 17.80% and 11.55%，respectively. Using the Primer 3.0，42 primers were designed and synthesized based on different dominant motifs types，and verified with R. roxburghii germplasms for validity and Rosa germplasms for transferability. The results showed that the products of 23 primers are clear and effective，23 pairs could be transferable to Rosa germplasms and 12 pairs were polymorphic among the 16 R. roxburghii germplasms. The results indicated that the unigenes generated from transcriptome sequencing in R. roxburghii can be used as an effective source todevelopment SSR markers. The large quantities of SSR markers will provide more reliable markers for map structure，analysis of genetic polymorphism for R. roxburghii and its closely related species.

Key words: Rosa roxburghii, SSR, transcriptome