Introduction: The Metformin and Acarbose in Chinese as the initial Hypoglycemic treatment (MARCH) trial has demonstrated a similar efficacy in HbA1c reduction between acarbose and metformin treatments in newly diagnosed type 2 diabetes mellitus (T2DM) patients. The current sub-analysis of the MARCH trail aims to evaluate the baseline characteristics that may influence the improvement of pancreatic beta-cell function and insulin resistance after acarbose therapy in Chinese patients with newly diagnosed T2DM. Methods: Of the 784 patients who entered the MARCH trail, 391 were assigned to the acarbose therapy group; 304 of these completed 48 weeks of follow-up of acarbose therapy. At 48 weeks, on the basis of the tertiles of change in homeostasis model assessment-beta cell function (Delta HOMA-beta) and homeostasis model assessment-insulin resistance (Delta HOMA-IR), the subjects were divided into lowly, mediumly, and highly improved groups. Results: In the highly improved HOMA-beta group, patients had higher systolic blood pressure (SBP), 2-h postprandial blood glucose (PBG), hemoglobin A1c (HbA1c), and lower high-density lipoprotein cholesterol (HDL-c), fasting serum insulin (FINS) concentration, and HOMA-IR in comparison to the lowly improved group (p < 0.05). A positive correlation was observed between HbA1c, SBP, and highly improved Delta HOMA-beta (p < 0.05), while an inverse correlation was evident between HDL-c and highly improved Delta HOMA-beta (p < 0.05). The highly improved HOMA-IR group had a significantly higher body mass index (BMI), fasting blood glucose (FBG), FINS concentration, and HOMA-beta in comparison to the lowly improved group (p < 0.05). A positive correlation was observed between FBG, waist circumference, and highly improved HOMA-IR (p < 0.05). Conclusion: Newly diagnosed T2DM Chinese patients with lower baseline HDL-c and higher HbA1c and SBP values are more likely to achieve improvement in beta cell function whereas baseline fasting blood glucose and waist circumference were the significant factors associated with improvement in insulin resistance with acarbose therapy.