A new strain CAU5501 (China patent application No. 200510066114.7), with high mycelial growth rate and high Ganoderma lucidum  polysaccharide-peptide complex (GPSPc) yield was obtained by UV(ultraviolet) induced mutagenesis on protoplasts of its parent strain (CAU55, Ganoderma lucidum).  After genetic stability test, it  was cultivated continuously for 10 generations on PDA slants and shaking bottles, the average growth rate (cm/7 d) of mycelium and the average yield of ex-PSPc (mg/mL) were improved 40.3% and 42.9% respectively compared with CAU55, showing that CAU5501 was a excellent strain with steady property, high mycelial growth rate and high GPSPc yield.  A feeding trial in broiler chicken was carried out to investigate the different effect of GPSPc and antibiotics on immune function, productive performance and carcassmerit of broilers. The data showed that GPSPc played important role on enhancing T-lymphocyte activity (+28.8%) and BSA antibody level (P <0.05), and stimulating the growth of thymus, spleen and bursa of Fabricius (+18.5%) compared with ones fedenramycin. It was found that GPSPc had better effects than enramycin on promoting the daily gain (P<0.01) in 1 to 4 weeks and growth of breast (+6.3%) and thigh muscle (+3.6%), and reducing abdomen fat (-18.6%) of broilers at 7 weeks. Based the comparison of on the efficiency between the two feed additives, it was proved that GPSPc was feasible for substituting antibiotics.