Changes in stem diameter of orchid plants were investigated in control growing climate. Previous study has focused on stem diameter in relation to plant water on terrestrial plant for outdoor and practice conventional watering by farmers. The objective of this work is to identify the characteristic of orchid stem changes and to relate the stem shrinking rate with orchid plant water content and its microclimate. In this project, strain gauge sensor was employed to measure the changes. Experiments were performed on two different samples of wild orchid, Coelogyne rochussenii and Epidendrum stamfordianum. From the finding, it can relate that changes in voltage strain gauge are related to the stem diameter of orchid plants. In conclusion, single strain gauge can be used in the measurement of the changes in stem diameter orchid plant.