The experiment was conducted to study the effect of diets with different protein levels on digestibility of nutrition substance and fur quality in female mink at the period of fur quality. Sixty of 90-day female mink, weighting an average of ��0.862��1±0.086��6) kg, were randomly assigned into six groups with ten replicates and one mink with each pen. The treatments were individually fed with26%(��), 28%(��), 30%(��), 32%(��), 34%(��) and 36%(��) protein levels in diets. The period of trial lasted for 100 days. The results showed that compared withgroup ��, group ��had significant differences in feed intake and dry matter of fence drain(��P��<0.05), greatly significant difference in digestibility of dry matter(��P��<0.01). On the item of net protein usage ratio, there was greatly significant difference between group ��and group �� (��P��<0.01) and significant difference when  group�� was compared with groups��, �� and ��(��P��<0.05). The biological value of protein has greatly significant difference between group��and group�� (��P��<0.01) and significant difference between group��and group��(��P��<0.05), the others had no difference(��P��>0.05). The fur length had significant difference when group��wascompared with groups��, �� and �� (��P��<0.05). The results indicated that  group ��had the best production performance in the biological value of protein and net protein usage when the protein level was 30% in the diet, basically satisfiedwith the requirements of female mink at the period of fur development. The fur length was obviously reduced when the protein level was lower than 28%.