Abstract: Potamogeton crispus is a carotene-rich Potamogetonaceae aquatic plant that is widely distributed in the Baiyangdian Lake in Hebei province, China. Laying rate, egg yolk color and egg quality of Chinese Ma duck was investigated in response to dietary supplements of P. crispus powder. Fresh P. crispus was harvested on May 12, 2009 and dehydrated with different drying methods. Total carotenoids in dried samples were ranked as freeze-dried powder (846.3 mg/kg DM)>air-dried powder (617.5 mg/kg DM)>sun-dried powder (362.7 mg/kg DM)>oven-dried powder (268.2 mg/kg DM). Nutritive composition of air-dried P. crispus powder was analyzed. Sixty 330-day-old Chinese Ma laying duck (body weight: 1.5±0.1 kg) were randomly arranged into A, B, and C groups (n=20 for each group). All ducks were daily fed on a fixed amount of 165 g corn-soyabean-meal basal ration before the start of this feeding trial. During the 12-d feeding trial period, the ducks in A group (control group) were still fed daily with the basal diet, while the ducks in B group were fed with fresh P. crispus ration (52.6% fresh P. crispus+47.3% basal ration), and the ducks in C group with air-dried P. crispus ration (20% dry basis P. crispus+80% basal ration). In both B and C ration groups the egg laying rate significantly increased by 7.9% and 4.2% respectively compared with that in A group (P<0.05), but there were no significant differences between B and C groups. There were no significant differences for egg shape index and egg weight between the three groups. Eggshell strength and thickness between C and A groups did not differ, but the eggshell strength and thickness of B group were significantly lower than those of A group (P<0.05). Harvey unit of egg in B group was significantly lower than that in A and C group (P<0.05), but there was no difference between the C and A groups. The egg yolk color of B and C groups significantly increased by 76.5% and 67.3%, respectively (P<0.05). Overall, air drying of fresh P. crispus effectively retained total carotenoids content. Dietary supplementation of air-dried P. crispus powder can effectively improve laying rate and significantly increase the color of egg yolk as well as other quality traits. These results may provide a reference guide of a rational use of Baiyangdian P. crispus to achieve a routine production of eggs with a red color in the yolk in laying ducks.