Potato chips industry is growing at a fast pace in India mainly because of increased availability of quality raw material (Anonymous, 2004). The cultivars Kufri Chipsona-1 and Kufri Chipsona-2 were bred specifically for chip making and were released for commercial cultivation in 1998 (Gaur et al., 1999). Both the varieties are long duration requiring 100–110 days for maturity (Gaur et al., 1999). But, still industry faces problem of raw material paucity during the months of December/January when stored material is not suitable and there is scarcity of fresh potatoes. Therefore, there is a requirement of cultivars with short duration maturity and for different seasons with reasonably good yields to increase the availability of raw material to run the industry round the year. To achieve these objectives either through conventional breeding or gene manipulations, it is essential to generate basic informations of tuber metabolism so that specific strategies could be adopted. Kufri Lauvkar is one such cultivar that achieves early maturity with good processing quality when grown in relatively warmer Malwa region of central India. But the cultivar fails to yield good processing quality, when grown in relatively cooler northern Indian plains. On the other hand, the exotic cultivar Atlantic performs very well with respect to processing quality under the same conditions. However, total tuber yields are higher in Kufri Lauvkar when compared with Atlantic. The north Indian plains are major potato producing regions of India. The study was, therefore, undertaken to compare the changes in sucrose, reducing sugars and dry matter content of tubers, which are major indicators of processing quality, between relatively poor processing cultivar Kufri Lauvkar and relatively good processing cultivar Atlantic to find out the possible reasons for poor processing quality of Kufri Lauvkar tubers.