Both genetic variation and harvesting season impact the amounts of bioactive compounds in Centella asiatica. This study investigated the seasonal influence on chemotypes and morphotypes and evaluated the genetic diversity of C. asiatica plants collected throughout Thailand. A total of 25 C. asiatica accessions was planted in the same area in Nakhon Sawan province and harvested during winter, summer, and rainy seasons. Results exhibited that variations in triterpenoid content were observed in different harvesting seasons, with total content of the four triterpenes highest during the summer season (5.98 %DW). Besides, we noted that the amount of phytochemical constituents (total phenolic, total flavonoid and total triterpenoid contents) and antioxidant were higher in winter and summer. The morphotypes were not influenced by season, while leaf area and leaf width negatively correlated with triterpenoid content. Based on chemotypes and morphtypes, we suggested the two elite accessions including Nakhon Prathom (NPT) and Nong Bua Lamphu (NBP) due to high centelloside content and large leaf. A total of 25 C. asiatica accessions was evaluated for genetic diversity by DNA fingerprints (ISSR, SCoT, and SRAP markers), resulting in a moderate genetic diversity, consisting of geography-related two populations without association with chemotypes and morphotypes. Our findings guide farmers in optimizing harvest times, and controlling centelloside content for future smart farming and insights on genetic diversity aid in future breeding and improvement of C. asiatica for medicinal industries.