Cover Story：This study focuses on investigating the transcriptome differences of testicular tissues in varying degrees of azoospermia patients through analyzing the differences of differentially expressed genes (DEGs) on levels of function, classification and metabolic pathways. One testicular tissue of non-obstructive azoospermia(NOA) and four testicular tissues of obstructive azoospermia(OA) (without sperm to having sperms by biopsies) were selected for RNA extractions, library constructions and sequencings by Illumina HiSeq^TM 2500, following with analyses including differential expression gene GO annotation and KEGG analysis. As a result, about 94.38% genome database were covered in the human reference genome and 2 242 transcripts were detected as predicted new protein-coding genes. Compared with NOA, 8 045 DEGs were up-regulated and 1 150 were down-regulated in OA1. For OA1 and OA2, there were 1 538 and 420 DEGs for down-regulation and up-regulation. For OA2 and OA3, there were 1 275 for up-regulation and 1 690 for down-regulation. The numbers of up-regulated (1 834) and down-regulated (1 853) DEGs between OA3 and OA4 were similar. KEGG enrichment analysis indicated that DEGs were mainly enriched in RNA degradation pathway, basal cell carcinoma pathway, cancer pathway, melanogenesis pathway and signaling pathways regulating pluripotency of stem cells. The expressions of PRM1, PRM2, TNP1, UBXN6, CXCL16, NUPR2, CCDC136 and CRISP2 genes showed an increasing trend with time-sequence specificity. In addition, different extents of gene fusions were found in 5 cases of azoospermia testicular tissue expressed genes. In summary, the number of DEGs and their function, classification and metabolic pathways were obtained with different degrees of azoospermia. The DEGs such as spermatogenesis and sperm motility were screened out, which enriched transcriptome information for azoospermia and laid a foundation for the research of testicular tissue related genes. It may provide theoretical basis for revealing the molecular mechanisms of spermatogenesis in azoospermia patients and promoting the development of male infertility research. Notably, gene fusion may be associated with azoospermia.