A total number of thirty two males and females, 35 to 40 days old growing New Zealand White (NWZ) rabbits were performed to investigate the effect of feeding rabbits on 8 diets with grade levels 10, 13, 16 and 19% of crude fiber (CF) incorporated with or without some enzymes (Caplix commercial product for multienzymes) supplementation at the level of 0.5 ml/1 litter water (as recommended by producing company) on performance, digestibility, some metabolic functions and the economic efficiency. Rabbits were divided equally into 8 groups containing 4 rabbits each. Each group contained 4 replicates, of one rabbit. The first four treatment groups were distributed to contain 10, 13, 16 and 19% fiber levels without enzymes. While, the other four treatment groups were distributed to contain the same previous fiber levels with enzymes. The experiment was terminated when birds were 17 weeks old (12 weeks of treatments). Body weight, weight gain and feed intake were recorded. Feed conversion (feed/gain) was calculated. At the end of the experiment blood samples were taken to determine some blood serum constituents and rabbits were kept for the digestibility experiment. The economic efficiency values were calculated. The data revealed that, rabbits fed dietary containing low (10 and 13%) fiber levels either with or without enzymes improve live body weight and body gain as compared dietary with high (16 and 19%) levels of crude fiber. Adding enzymes supplemention improved body weight gain for rabbits fed dietary 10% CF during the entire period. Adding enzymes reduced feed intake for rabbits fed dietary CF at all levels (10, 13, 16 and 19%) compared with other same dietary CF without enzymes additions, during all experimental period. Feed conversion efficiency improved for rabbits fed (10 or 13%) CF either with or without providing enzymes compared with rabbits fed high fiber diets (16 and 19% CF). Rabbits fed 10% CF and provided with enzymes recorded better (P<0.05) values of dry mater (DM), crude protein (CP) and crude fiber (CF) digestibility. Also, it recorded the best total protein (TP), total globulin (TG) total lipids (TL) and glucose compared with other dietary levels of fiber. The higher values of (GOT) and (GPT) was recorded for rabbits fed dietary 16% CF and providing with enzymes compared with other dietary enzyme. The greatest total revenue and profit were calculated for rabbits fed diet contain 10% CF and provided with enzymes as compared with other dietary treatments.