ObjectiveThis study aimed to investigate the association between baseline albuminuria and the progression of diabetic kidney disease (DKD) in patients newly diagnosed with type 2 diabetes mellitus (DM). MethodsA retrospective cohort study was conducted among 604 patients aged ≥18 years who were newly diagnosed with type 2 DM between January 2014 and 31 December 2017 at an outpatient clinic in a tertiary hospital in China. The incidence of albuminuria was determined and the associations between albuminuria at baseline and the progression of DKD estimated by estimated glomerular filtration rate slope were evaluated using binary logistic regression analysis. ResultsAt diagnosis of type 2 DM, 18.8% of patients had albuminuria, with 17.4% having microalbuminuria and the other 1.4% having macroalbuminuria. During the 5-year follow-up period, patients with albuminuria at the baseline experienced a more rapid decline of estimated glomerular filtration rate over time than patients with normoalbuminuria at baseline (−2.6 vs −1.5 mL/min/1.73 m2 per year, P =.01). Albuminuria at baseline is independently associated with the progression of DKD. ConclusionsThe prevalence of albuminuria is 18.8% in patients newly diagnosed with type 2 diabetes and the occurrence of albuminuria can predict steeper annual decline in kidney function.