Comparative genomic analysis constitutes a powerful approach for the systematic understanding of genome. The comparative and evolutionary analysis of known microRNAs in Homo sapiens elucidates the discovery of the existence of the novel non-coding RNA, which is transcribed from the unique gene precursor and produces three different non coding RNAs such as piRNA, snoRNA and microRNA. This new characteristics RNA is named as x-non coding RNA (x-ncRNA). This characteristic pattern shows evolutionary signatures dictated by its precise selective significance and synteny. The evidence of xncRNA processing and functionality from hairpin arms were proven by systematic analysis. x-ncRNA analysis proven the bio genesis of human piRNA is originated from the dsDNA, which is also involved in the synthesis of piRNA and/or microRNA, through dicer. These data also shows the presence of human sno-microRNA. Our data demonstrates that the existence of x-ncRNA, genomic origin, conceivable bio genesis pathway, evolutionary relationship and its functions
