Understanding the relationship between root system and yield related traits is an important objective in crop breeding programs. Canonical correlation analysis has been adopted to study the strength of association between the root morphological traits and grain yield components under low-moisture stress and well-watered conditions and to find the root morphological characters that have the largest influence on grain yield and its components under the two conditions. This study revealed that root to shoot length and weight ratios and root dry weight were had the largest effect on plant height, shoot dry weight and grain yield under well-watered condition. Under low moisture stress, maximum root length and root number were also important for improving grain yield and panicle length. The interrelationships clearly identified the importance of root to shoot length and weight ratios and root dry weight under well-watered condition. While, maximum root length and root number are a better combination under low moisture stress condition.