Technical Abstract: Resistance in peanut to CBR was inoculum-density dependent. Greenhouse resistance screening can be conducted with standardization and more uniform distribution of inoculum and time efficiency. In order to two develop a accurate and repeatable screening method to identify resistance to CBR in the greenhouse, two experiments were carried on with two peanut cultivars, Georigia-02C and C99R in Tifton, GA from 2005 to 2006. Based on root rot severities, Georgia-02C showed higher resistance to CBR than C99R in both experiments, which was similar with the field performance of the two cultivars. In the microsclerotium-soil mixed inoculation test (method I), root rot severity at the same inoculum density was significantly higher for large microsclerotia (>250µm) than for small (75~150µm) and medium (150~250µm) sizes. In the post-emergence inoculation test (method II), there was no significant difference among the root rot severities of different microsclerotia size categories. The recommended inoculation level was 1~5 ms/g soil for both of the methods, although method I produced more severe root rot than method II at the same inoculation level.