The research was carried out to assess the effect of vermicompost and tuber size on the changes of TSS (total soluble solids), sucrose (non-reducing sugar) content, and skin color of potato under ambient storage condition. Potato variety BARI TPS-1 was used as an experimental crop. The experiment was consisted of two factors, i.e., factor A:-Vermicompost level (Vm1-4): Vm1: 0 t ha-1 (control), Vm2: 3 t ha-1 , Vm3: 6 t ha-1 and Vm4: 9 t ha-1 ; factor B:-Tuber size (T1-5): T1: 5-10 g, T2: 10-20 g, T3: 20-30 g, T4: 30-40 g and T5: >40 g. The research exhibited that vermicompost had a significant effect on most of the quality contributing parameters investigated under the experiment. Results exhibited that processing quality parameters increased with increasing vermicompost level irrespective of tuber size. Among the twenty (20) treatment combinations, vermicompost at the rate of 9 t ha-1 with tuber size >40 g produced the minimum total soluble solids (4.55% Brix), minimum sucrose (0.2947 mg g-1 FW) and maximum skin color (L* 67.38, a* 15.38, b* 26.60). In respect of ambient storage condition total soluble solids (TSS), sucrose slowly increased with increasing storage time up to 40 days after storage (DAS) and finally became non-suitable for both table and processing purpose; while skin color decreased with increasing storage time. Therefore, the study suggests that potato growers may use vermicompost for improving processing quality of potato varieties and can store potato up to 40 DAS at ambient storage condition.