Timber is an important source of income. In the past, the sampling method of fixed-area plots was used to calculate the estimated volume with the volume equation or volume table. However, the volume equation will be affected by the data at the time of establishment, resulting in estimation deviation. Therefore, it is necessary to seek a more efficient and accurate method. This study compared the efficiency of horizontal sampling (HPS) combined with volume equation and critical height sampling (CHS) in estimating the volume of Cryptomeria japonica and Taiwania cryptomerioides plantations in Taiwan. It turns out that the result of CHS didn’t fluctuate with the volume equation and took less time during the survey, which can improve the efficiency of sampling.