A total of 30 Zaraibi lactating goat does (42.46±0.86 kg LBW and 4-5 years of age) were used in this study to investigate the effect of partially replacing concentrate feed mixture (CFM) containing cotton seed cake in the diet by two levels of sunflower seeds (SFS), being 15 % (G₂) and 20 % (G₃) on chemical composition, digestibility coefficients, rumen liquor parameters and live body weight of Zaraibi goats. At the last month of pregnancy, goat does were divided into three similar groups (10 in each). Goat does in the 1^st group (G₁, control) were fed a basal ration containing 25% CFM and 75% fresh berseem (FB) during winter feeding or 50% CFM and 50% berseem hay (BH) during summer feeding. During an experimental period from 30 d pre-partum up to the next mating season, does in all groups were biweekly weighed. Two digestibility trials were conducted during the suckling period (winter feeding) and mid of the lactation period (summer feeding). Results revealed that contents of EE and OM % were higher, while contents of DM, CP and ash were lower in SFS treatment groups than in control group. However, contents of CF and NFE % were nearly similar in SFS and CFM treatment groups. ًWinter feeding was characterized by higher CP (about 15 vs. 13%) and lower CF (about 12 vs. 16%) than summer feeding. By increasing level of SFS from 15 to 20 %, only digestibility coefficients (DCs) of DM, OM and EE increased (P<0.05) during winter feeding; however, DCs of all nutrients, except of CP, increased (P<0.05) during summer feeding. During the winter and summer feeding, nutritive value of experimental rations as TDN increased (P<0.05) by increasing level of SFS, while nutritive values as TDN or DCP was higher (P<0.05) for both SFS levels, being the highest for 20 % SFS diet. Inclusion of both SFS-levels during winter feeding increased (P<0.05) pH value and decreased concentration of VFAs, but did not affect ammonia concentration in ruminal liquor (RL). Only 20 % SFS diet decreased (P<0.05) pH value and increased concentration of VFAs and ammonia in RL sampled before or post-feeding during summer feeding. The differences in live body weight of does among the experimental groups and within each group were not significant (P≥0.05) at different experimental periods. It could be concluded that replacing 20% of CFM by sunflower seed has beneficial effects on digestibility coefficient and nutritive values without marked change in rumen liquor parameters and goat performance.