An investigation was carried out to find out the nutritional parameters viz. consumption, assimilation and tissue growth etc. of muga silkwormAntheraea assama Westwood (Lepidoptera: Saturniidae) by rearing it indoor on som twigs. During 32 days of its larval life, the total consumption of an individual was 33·925 g of which 21·295 g were assimilated by the insect. About 80·1% of the total consumption took place in the fifth instar alone. The weight of one full grown larva was computed at 13·9304 g. The assimilation and tissue growth were found positively correlated with the consumption as well as with the age of the larva. The approximate digestibility was negatively correlated to the amount of food consumed. Efficiency of conversion of ingested and digested food increased in the first 4 instars and declined in the fifth instar.