To provide a method for evaluating the degree of ripening of an organic material such as a compost by which the evaluation can be carried out in a short time according to simple operations.

A culture medium for evaluation containing an extract from an organic material such as a compost is prepared and a culture medium for control without containing the extract from the organic material is further prepared. The culture medium for evaluation and the culture medium for control are then respectively sowed with seeds for tests. Bean sprouts predipped in water are used as the seeds for tests. The seeds of the bean sprouts have a larger size than that of seeds of Brassica rapa var. pervidis and have a higher growth rate than that of the seeds of the Brassica rapa var. pervidis. The bean sprouts in each culture medium are germinated and grown. Each seed of the bean sprouts is grown into a plantlet 6 having a root 1, a lower hypocotyl 2, an upper hypocotyl 3, first leaves 4 and cotyledons 5. The germinated conditions and growth conditions of the plantlet 6 for each culture medium are compared to thereby evaluate the degree of ripening of the organic material. For example, the lengths L1, L2, L3 and L4 of respective parts of the plantlet 6 are measured as the growth conditions.