The glomerulus is a capillary tuft that finely filters blood and is a culprit place affected by diabetic kidney disease. To advance our understanding of glomerular cells in normal and diabetic kidneys, we created an integrated 59,382 cell census from db/+ and db/db mouse kidneys by single-cell RNA sequencing after isolation of glomerular cells. Cellular network analysis showed disrupted cross-talk among glomerular cells, with Tgf-β1 and Tnf from immune cells being common influencers. Based on gene expression patterns, we identified the potential function of parietal epithelial cells (PECs) with their heterogeneous cell states and characterized podocytes into healthy, stressed, and dedifferentiated podocytes. We applied these diverse cell states to reconstruct that the combined trajectory of podocyte regeneration in normal kidneys and podocyte injury is predominant in diabetic kidneys. Using transcriptional profile and gene regulatory network, we revealed that podocyte regeneration recapitulates podocyte development. Collectively, our study provides new insights into PEC and podocyte biology in health and diabetic kidneys with a comprehensive atlas of mouse kidneys.