BACKGROUND: Obstructive nephropathy (ON) is caused by obstruction of urine flow, featured with progressive renal dysfunction and progressing into chronic kidney disease. There is still controversy whether to remove the kidney or simply relieve obstruction in patients with late diagnosis. Reliable biomarker is needed for predicting renal function reversibility in ON patients. As the frontier in non-coding RNA research, circRNA is involved in the pathological progress of ON, however, the correlation between hsa_circ_0012138 expression and renal function reversibility remains unknown. METHODS: RT-qPCR and RNA-fluorescence in situ hybridization (RNA-FISH) to identify hsa_circ_0012138; Bioinformatics analysis: Gene Set Enrichment Analysis (GSEA); Clinical data analysis: the receiver operating characteristic (ROC) curves. RESULTS: In this study we identified hsa_circ_0012138 expression in the kidney tissue by RT-qPCR. By GSEA enrichment, we speculated that it may regulate the expression of multiple target genes related to renal fibrosis through ceRNA mechanism. We further detected its expression in urine of ON patients with different stage. Combined with the other clinical variables, statistical analysis found that, compared with NAGL, hsa_circ_0012138 has good specificity and sensitivity in prediction the renal function reversibility after kidney-sparing surgery in ON patients, and is expected to be used as a prognostic marker to guide surgical decision-making.