TECHNOLOGY FOCUS - BIOLOGY - Preferred Process: The grass extract is prepared by: adding 10 times of grass with 70% ethanol as solvent, soaking and extracting at 70 degrees C for 2 times and 1 hours, filtering, recovering the ethanol, and concentrating and drying to obtain an extract A; adding 20 times of water into the extract A, filtering to obtain medicine liquid A and precipitate A, adding hexane-ethyl acetate-methanol-water (2: 2: 3: 2) as solvent into the precipitate A, separating and purifying, recycling the solvent, and concentrating and drying to obtain an extract B; passing the medicine liquid A through a HPD 600 macroporous adsorption resin, eluting by water and then by 70% of ethanol solution, collecting different concentration of ethanol eluent, recycling the ethanol, and concentrating and drying to obtain an extract C; and uniformly adding and mixing the extract B and the extract C.    TECHNOLOGY FOCUS - ORGANIC CHEMISTRY - Preferred Components: The mass content of extract B is 10-90 wt.%, preferably 3-70 wt.%. The extract B comprises insect moulting hormones; alepterolic acid; ent-2- beta -hydroxyl-16-ene-kaurdn-19-oic acid; 8(17),13 (E)-labdadien-15, 19-dioic acid; methyl 8(17),13(E)-labdadien-19-oicacid-15-oate; 15-acetoxy-8 (17), 13(E)- labdadi-en-19-oic acid; 15 -hydroxy-8 (17), 13 (E)-labdadien-19-oic acid; 8(17), 13(E)-labdadien-15,19-diol; 19-hydroxy-8(17), 13(E)-labdadien-15-al; 19-hydroxy-8(17),13(Z)-labdadien-15-al; 8(17), 13(E)-labdadien-19-oic acid-15-al; 8(17), 13(Z)-labdadien-19-oie acil-15-al; 16 beta -hydroxy-17-((Z)-p-cotunaroyl) en-t-kauran-19-oic acid; 19-hydroxyl-17-nor-16-ene-kauranone; ent-16 alpha , 17, 19-trihydroxylkaurane; and ent-16 alpha , 17-dihydroxyl-kauran-19-oic acid. The mass content of the extract C is 15-80 wt.%, preferably 40-80 wt.%. The extract C comprise: onychin; onychin-2'-O- beta -D-glucoside; onychin-2'-O- beta -D-alloside; A(2(R)-5, 7, 3'-trihydroxy-6, 8-dimethyl, 5'-methoxynavanone-7-O- beta -D-glucopyranosid); B(2(R)-5, 7, 3'-trihydroxy-6, 8-dimethyl-5'-methoxvnavanone-7-O-(6''-O-(3'''- hydroxy-3'''-methylglutaryl)- beta -D-glucopyranoside)); C(2(R)-5, 7, 3'-trihydroxy-6, 8-dimethyl-5'-methoxvnavanone-7-O-(6''-O(5'''-butoxyl-(3'''-hydroxy-3'''-methylglutaryl)))- beta -D-glucopyranoside); hesperidin; naringin; and homoeriodictyol.    TECHNOLOGY FOCUS - POLYMERS - Preferred Components: The macroporous adsorption resin comprises X-5 macro-porous adsorption resin, LSA-40 macroporous adsorption resin, AB-8 macroporous adsorbent resin, HPD600 macro-porous adsorption resin, D301R macroporous adsorbent resin, NKA macroporous adsorption resin, and ADS-8 macroporous adsorption resin. ACTIVITY - Antidiabetic.    ADMINISTRATION - Administration of the grass extract is orally in the form of tablet, granule, or capsule (claimed).