In order to determine the optimal supplemental levels of methionine and cysteine in diets and their correlations of influences on growth and hair coat development of Rex rabbits, the related indices of growth and hair development were measured. A total of 315 new born Rex rabbits with the same birthday were allocated into 7 groups at random in litters. There were 7 replicates in each group and 6 rabbits in each replicate. The rabbits in the control group were fed a basal diet which contained 0.24% methionine and 0.23% cysteine, and the rabbits in the experimental groups were fed the diets supplemented with 0.10%, 0.25% and 0.40% methionine or cysteine based on the basal diet, respectively. The feeding trial lasted from birth to 151 days old. The results showed as follows: supplementation of sulphur-amino acids could increased the body weight at 151 days of age and average daily gain, and above indices in the 0.25% and 0.40% groups had significant differences compared with the control group (P<0.05). With the supplemental level of sulphur-amino acids increasing, the feed to gain ratio showed a declining trend (P>0.05), while the average daily feed intake showed an increasing trend (P>0.05). Compared with the control group, completion ratio of molt and hair coat density in the 0.25% and 0.40% groups were significantly increased (P<0.05 or P<0.01), but no significant differences were found between 0.25% and 0.40% groups (P>0.05). From the perspective of hair coat scores at 92 and 151 days of age, supplementation of sulphur-amino acids could not significantly boost the hair coat quality of rex rabbits (P>0.05), and hair coat quality only showed an increasing trend with the supplemental level increasing. No significant differences were found in the above indices between methionine and cysteine groups with the corresponding levels (P>0.05). Growth curve-fitting suggested that supplemental level of sulphur-amino acids could only change the maximum growth rate, but had little effect on the adult body weight. These results indicate that both of methionine and cysteine can promote growth and enhance hair coat development of Rex rabbits, and 0.25% dosage is the optimal supplemental level. Moreover, the promotive effect of the methionine and cysteine almost is alike, and the equivalent cysteine may entirely replace methionine. However, supplementation of sulphur-amino acids only can not significantly boost the hair coat quality of Rex rabbits.