Abstract: Inulin containing tubers of Jerusalem artichoke (Helianthus tuberosus L.) can be used as raw material for healthy products, sweeteners, bio-ethanol and animal feed. The objective of this study was to evaluate the effects of cultivar, environment and cultivarxenvironment interaction on fresh tuber yield tuber number and tuber size of Jerusalem artichoke. Fifteen cultivars were evaluated in a randomized complete block design with four replications at nine environments in the Northeast of Thailand. Differences among cultivars were observed for fresh tuber yield, tuber number and weight of individual tubers (tuber size). Environment effect contributed to a larger portion of variations in fresh tuber yield, tuber number and tuber size. Although, genotypex environment interactions were also significant, their values were much smaller than genotype main effects for all characters. Stability parameters indicated that exploitation of superior cultivars with adaptation to a wide range of environments and the cultivars with specific adaptation to specific environments would be possible. Low correlation but significant was found for fresh tuber yield and tuber number, indicating that tuber yield in some cultivars was dependent on high tuber number. Strong correlation between fresh tuber yield and tuber size indicated that bigger tuber is necessary to obtain higher tuber yield. Negative but significant correlation between tuber number and tuber size indicated that increased tuber size is on the expense of tuber number. JA 89 was the most promising cultivar for wide adaptation and high tuber yield, whereas HEL 65 was the most promising cultivar for its bigger tubers and acceptable yield.