The most attractive product from pyrolysis of biomass is the liquid phase. The nature of conversion of cotton cocoon shell by pyrolysis to liquid products has been studied in the presence of alkali additives. The final temperature limits of the pyrolysis processes were 620-820 K. The yield of conversion with Na2CO3 additive (20% by weight) to liquid and gaseous products increased from 63.8% to 73.0%, while the final pyrolysis temperature was increased from 620 to 820 K. While the liquid yield was 48.8% at a pyrolysis temperature of 620 K, at the final pyrolysis temperature of 820 K, the oil yield decreased to 32.2%. The yield of conversion with K2CO3 additive (20% by weight) to liquid and gaseous products increased from 65.5% to 73.7%, while the final pyrolysis temperature was increased from 620 to 820 K. While the liquid yield was 53.5% at a pyrolysis temperature of 620 K, at the final pyrolysis temperature of 820 K, the oil yield decreased to 30.2%. The yield of liquid increased only 3.1% in the presence of Na2CO3 (20% of the sample) at 620 K. Indeed, the highest yield of liquid was 7.5% in the presence of K2CO3 (20% Of the sample) at a final pyrolysis temperature of 620 K.