Introduction To compare glycemic variability (GV) and time in range (TIR) in Chinese patients with type 2 diabetes (T2D) initiated on once-daily bedtime insulin glargine 300U/ml (Gla-300) versus neutral protamine Hagedorn (NPH) insulin using continuous glucose monitoring (CGM). Methods This was a 24-week, open-label exploratory study with 1:1 randomization comparing patient-adjusted titration of Gla-300 ( n  = 23) versus NPH ( n  = 23) at bedtime in insulin-naïve T2D patients on maximum oral glucose-lowering drugs. The starting dose was 0.2 U/kg/day and with self-titration of one unit per week to achieve a target fasting glucose of 4.4–6 mmol/l, without hypoglycemia. Participants had masked CGM at baseline, weeks 11 and 24. The primary outcome was between-treatment differences in CGM glucose standard deviation (SD) at week 24. Results HbA1c at week 24 were similar, with 21% of Gla-300 versus 4% of NPH-treated patients achieving HbA1c < 7% without confirmed hypoglycemia. There were no differences in anytime glucose SD at week 24 (LS mean difference − 0.08 mmol/l, 95% CI − 0.42–0.26, p  = 0.63). Anytime %TIRs (3.9–10.0 mmol/l) at week 24 were similar ( p  = 0.91). Nocturnal % time below range < 3.9 mmol/l was significantly lower in the Gla-300 group (least squares (LS) mean difference – 5.03% − 9.92 to − 0.14, p  = 0.04) with lower % coefficient of variation (LS mean difference − 4.5% − 8.1 to − 0.8, p  = 0.018). Diurnal TIR was higher in Gla-300 patients at week 11 but there were no differences at week 24. Conclusions Once-daily bedtime Gla-300 was associated with lower nocturnal GV, time below range and self-reported hypoglycemia in insulin-naïve Chinese T2D patients over a 24-week study period, as compared with NPH insulin. Clinical Trial Registration ClinicalTrials.gov Identifier: NCT03389490.