Percentage of coloured cocoons in the population of Antherae paphia Linn. was studied in three different altitudinal ranges in Mayurbhanj districts of Odisha. It was observed that the percentage of population of black cocoons was highest in the lower altitude in the range 100-300mASL.The percentage of population of grey black cocoons was found to be highest in medium altitude in the range of 301-600mASL as well as in higher altitude in the range 601-1000 mASL. The percentage of population of grey cocoons was recorded to be second highest and similarly the percentage of population of yellow black cocoons indicated second highest value in medium altitude.The percentage of population of black cocoons occupied second position in higher altitude and the population of yellowblack cocoons was found to be lowest in percentage.The occurrence of yellowgrey cocoons in medium altitude was not observed.Incase of higher altitude the existence of population of yellowgrey cocoon,brown cocoon and grey cocoon was not detected.The variation in percentage of population of different coloured cocoons studied in different altitudes indicated significance difference as based on t-test and Anova test.The probable reason of marked variation of population of different coloured cocoons based on altitudinal gradient might be due to the effect of variation in prevailing annual temperature,relative humidity,photoperiod etc. which needs to be studied in depth for future conformation.