Eri silkworms’ primary food is castor oil plant leaves, which is readily available and grows naturally in the wild and semi-arid areas which was the first and best host plant for eri silkworm production. It has been showed a difference production potential within castor varieties and also the effect of castor which is growing in the research station on performance of Eri-silkworm does not studied previously. Therefore, the objective of the present thesis was to investigate the effect of castor varieties on rearing performance and feeding efficiency of Eri silkworms (Philosamia Cynthia ricini in Shewa Robit research station of Debre Berhan University. The study have been taken the time from march24/2020 to May18/ 2020 .In this study six castor varieties (Abaro, Hiruy, Acce20895012, Acce212534, Acce219671 and Local) were evaluated in the laboratory condition using CRD model and the analysis method was done with SPSS +(version 20) software 2019/2020 by feeding the same quantity of different castor varieties for all treatment with replications .The results showed that feeding of different castor varieties influenced the rearing performance and feeding efficiency of Erisilkworms Philosamia Cynthia ricini. In case of rearing performances (larval, cocoon and grainage) parameters Hiruy showed best rearing performance and Acce219671 that showed best rearing performance on larval and cocoon but not grainage parameters. Abaro was the third better feed plant for eri-silkworms Philosamia Cynthia ricini. The effect of castor varieties on feeding efficiency of erisilkworm (Philosamia Cynthia ricini) in terms of food consumption, food assimilation, assimilation efficiency and growth rate of larvae during feeding time (in days) were evaluated in the stage of fourth and fifth instar of larvae development. Thus all parameter of feeding efficiency measurement the three castor varieties (Hiruy, Acce219671 and Abaro) were the best feed plant for rearing of eri-silkworms Philosamia Cynthia ricini in the present study. The mean body weight of the larvae was highest for eri-silkworms fed on the leaves of Hiruy, Acce219671 and Abaro and this leads to high growth rate. Feeding efficiency (FC, FA, GR and MBWL) and rearing performance have showed that positive relation in most and required parameters (MLW, ERR, CW, SW and PW) and negatively correlation on hatchability of an egg The high quality and quantity of feed is required to get the best cocoon and shell weight but not for hatchability due to optimum temperature and relative humidity are mandatory for hatchability after egg laying rather high amount of feed. Even if Hiruy, Acce219671 and Abaro identified for better rearing performance further study shall be recommended for performance of Local castor varieties which has the best rearing performance of eri-silkworms.