Apparel industry is one of the oldest and among the most global industry being primary concerned with the design and production of cloth and their supply. The central process in the apparel manufacturing is the joining together of Garment components which is known as the sewing process , which is the most labour intensive type of manufacturing process.Proper Utilization of resource in garment sewing section is more critical to enhance performance of the apparel industry with reducing production cost and minimizing wastage. For effective utilization of resource in sewing section good line balancing is important in order to increase productivity and production efficiency This research was design to analyse and improving assembling line in case of Telaje garment manufacturing and sales private limited company.Study was first conduct observations in production floor and start work with the selection of sewing line in garment production process. Among nine lines of the factory select one on the production floor and one garment ordered product known us five pockets men‟s jeans trouser. For this study both qualitative and quantitative research approaches were employed. Both primary and secondary data source are used to detailed collected relevant data to accomplish this thesis works. The main problems facing with Telaje garment manufacturing and sales Plc are: irregular material flows, long production lead time, bottlenecking, and low productivity. To eliminate the problems implementation of proper line balancing is mandatory,However,Telaje garment manufacturing and sales Plc do not implement proper line balance in production system due to lack of skill and nature of difficulty of line balancing when they want to change or modify the assembly line, therefore this thesis work shows that bottleneck process and consequence solution would be searched, and significantly improving productivity by 387 unit product/ day and, hence Line efficiency would increase from 29.1% to 50.04% of the line.