| Nowadays, primary productivities on Inner Mongolia grassland have been severely reduced due to unrational utilization, and consequently, animal production in the grassland regions were greatly affected. The principlal reason for this fact is long term mal-management for the grassland resources. This study focuses on the regrowth behaviours of main herbage plants and investigated the effects of cutting intensity and cutting time on the regrowth capacity of the plants in the typical grassland zone in Inner Mongolia. Detailed investigation results were as follows:1. The study region had 51 plant species belonging to 18 families and 42 genera. Plants specific diversity is low. Most of the plants are gramineous plants. Vegetation distribution is not even and grassland coverage was about 20%—60%.2. The Gramineae plant's main regrowth patterns were top upgrowth, leaf enlongation and budding from rhizomes. Compositae plant's main regrowth patterns are new branches produced from axilluary budes, from rhizomes and leaf and interspace enlongation. In leguminous plants, high palatable legumes, with the regrowth pattern of budding from rhizomes were not suitable for cutting use. By contrary, poor palatable legume plants such as Thermopsis lanceolata, Oxytropis racemosa which had regrowth of axiluary budes and rhizomatous buds had fairly strong regowth ability. Other plants, due to their different biological habits,their regrowth patterns were varied.3.Under different cutting intensity conditions, Leymus chinensis showed best regrowth performance under moderate cutting treatment in terms of residue survival, regrowth rate, regrowth intensity and yield. More singnificant difference (P<0.10) in regrowth rate existed between moderate cutting treatment and the non-cutting control; Yield in the moderate cutting treatment was higher than the non-cutting control (P<0.05). Similar responses were found for stipa grandis. Best regrowth was found for Agropyron mongolicum under heavy cutting treatment in terms of regrowth rate, regrowth intensity and yield. Significant differentce was found in regrowth rate for agropyron mongolicum between heavy cutting treatment and the non-cutting contrl(P<0.05). Heavy cutting depressed the regrowth of Cleistogenes squarrosa. For Serratula centauloides, the yield of moderate cutting treatment was higher than that of heavy cutting treatment, but lower than that of non-cutting control treatment. The results explained that cutting could affect Serratula centauloides's aboveground regrowth. Heavy cutting could promote Heteropappus altaicus's aftermath yield. There were significant differences in regrowth rate and yield between the heavy cutting treatment and the non-cutting control (P<0.05).The leguminous plants of high palatability such as Melissitus ruthenius and Astragalus adsurgens were intolerant to cutting utilization.4. After late July or early Augest, Leymus chinensis's regrowth capacity began to drop. its regrowth were affected by cutting time obviously. By contrary, Stipa grandis's regrowth capacity was lessly affected by cutting time.5. One time cutting in a year (middle May or early June, namely May c1y1 or June c1y1 ) or two times cutting in a year (first cutting in middle May, second cutting in early Augest, namely May y1c2 ) could improve cummunity's above ground biomass. There was a significant difference between May c1y1 and non-cutting treatments (P<0.05). And also there was a more significant difference between Jun y1c1, May y1c2 and non-cutting control (P<0.10). Successive cutting in every years affected grassland's well-balanced growth.6. Based on the consideration of plant's cutting tolerance, cutting intensity and grassland productivity, the result indicated that moderately cutting or grazing utilization in middle May or early June were considered suitable for the grassland.The research results also indicated that May c1y1, June c1y1 system or May y1c2 system were suitable management measure to promote above-ground biomass accumulation.
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