Abstract: One of the means to promote the continuous perfaction of the management measures of natural resources is to provide some method for calculating or evaluating the utilization prospect of terrestrial plant resources. Taking the medicinal ferns of Zhejiang Province as an illustrative example, a method to this end is put forward by the author of this article.What makes it possible for this method to obtain the estimation value of the possible utilization amount is the five elements and the three-figure grades of each of them. The five elements are habitat (H), regenerative ability (R), frequency (F), abundance (A) and utilization (U). H and R are basically constant without variation, and F and A continue to use the conventional method of phytocoenology with the only difference that the scope of assessment is extended from a model plot of definite area to that of a natural region of vegetation or an administrative division. Only the element of utilization is subject to great changes, owing to the influence of human beings. This makes it the most important element of the five.The actual management of terrestrial plant resources(U)is based on the accumulated value V of the grade figures of the five elements, namely the assessed possible amount for utilization expressed in numerical value. But as it is possible that man’s subjectivity exists on the determination of the grades of management of natural resources, so it is requested that the actual situation of such resources be examined and checked again and again before any final decision is made.