Abstract: The cDNA library of 50-500 nt ncRNAs in Bombyx mori were constructed,and a small RNA Bm-86 accumulated more in larva and pupa during development was found.To further dissect the function of this ncRNA,bioinformatics analysis,northern blot and RT-PCR were taken out.Results showed that Bm-86 was an H/ACA box small nucleolar RNA,located in the second intron of eIF5A,with no predicted pseudouridylation modification site in rRNAs,snRNAs and tRNAs of B.mori.Moreover,a putative promoter were located 26...