Evenness is one of the main criteria characterizing quality for any staple spun yarn. Variation in yarn mass have significant influences like the other quality parameters of jute spun yarn for being applied in the diversified items. However, jute flyer spinning frame had been modified in the drafting zone to improve the quality parameters of jute yarn. In this study, mass variation (unevenness) results of jute yarn had been investigated by producing two types of jute yarn counts (i.e., 6.5 and 10 lbs/spy) for both the existing and the modified spinning frame. Hence, the results of jute yarn unevenness values had been compared between the modified and the existing spinning frame. Results revealed that mass variations of jute spun yarn had been decreased for the modified spinning frame for the both counts (i.e., 6.5 lbs/spy and 10 lbs/spy). Finally, it was remarked that the modified spinning frame produced a better quality of jute yarn in terms of mass variation compared to that of the existing spinning frame.