Abstract: Ulos is a traditional woven from the tribe of Batak in the form of scarves. It is commonly used in the Batak traditional ceremonies. Ulos such as other Indonesian traditional woven, yet rapidly developed in the industry because the production is still traditional and manual. Besides, the design of their motifs is still particularly aimed for ceremonial purpose only. Accordingly, we conduct a study to develop software called jTenun that is able to generate new motifs of Ulos but still have specific characteristics of Ulos. The development is based on existing software called jBatik that has been successfully developed and widely used to generate a new motif of Batiks. jBatik was developed using L-System, a programming language which is able to create a pattern by making use of the iteration concept. Due to the same repetition characteristics of Batik and Ulos, L-System is also applicable to generate new pattern of Ulos. Hence, it is also used in this study. The result shows that jTenun is able to generate new patterns of Ulos as confirmed by some Ulo’s experts in the evaluation phase of this study.