The content of tenacissoside H in Xiaoaiping pills was determined, and the stability of it was studied. The content of tenacissoside H in Xiaoaiping pills was determined by HPLC-ELSD. The content of tenacissoside H in Xiaoaiping pills was determined under the following conditions: (1) at (25±2)°C, relative humidity of (60±10)%, keeping for 0, 3, 6, 9, 12 mo;(2) at (30±2)°C, relative humidity of (65±5)%, keeping for 0, 1, 2, 3, 6 mo; (3) at (40±2)°C, relative humidity of (75±5)%, keeping for 0, 1, 2, 3, 6 mo. The linear range of tenacissoside H was 0.390 2-3.902 0 μg(r=0.998 0) with an average recovery of 99.03% (RSD=1.75%, n=6). The content of tenacissoside H kept stable under the condition of (1) but not stable under the condition of (2) and (3). The method is accurate and feasible, but tenacissoside H can not used as quality control index of Xiaoaiping pills.