Abstract: In this study canonical correlation analysis has been used in order to better understand the relationship between and among root morphological characters and yield components, under non-stress and stress conditions in rainfed lowland rice. This study revealed that maximum root length was the root morphological character that had the largest effect on plant height, panicle length and panicle number under non-stress conditions. Under low-moisture stress, root volume was also important in addition to maximum root length. In toto, the results of this study has shown that maximum root length and root: shoot dry weight are the characters of choice for improving grain yield under well-irrigated conditions, while maximum root length and root volume are a better combination under low moisture stress conditions.