The extinction of some of medical plants is not only due to the overuse of them and the grazing pressure but also their incorrect exploitation methods. Ferula assafoetida is one of the most important medical plants in Iranian rangelands, which is gradually disappeared from its habitats due to destructive traditional exploitations. Therefore, in order to determine how different incision techniques (exploitation methods) affect F. assafoetida properties, a study was carried out in the research field of Agricultural and Natural Resources Research Center in Mashad, Iran from 2009 to 2010. F. assafoetida plants were five years olds. The plants were cultivated in four densities in the field (25´50, 40´50, 55´50, and 70´50 cm) and four incision treatments as horizontal cutting (traditional), 45-degree cutting, concave cutting and non-incision (control) using a split plot design based on the completely randomized block design with three replications. In each plot, three plants were selected and leaf area, number of leaves, basal diameter, dry matter of post-harvest leaves and survival rate were measured. Analysis of variance of data was conducted and means comparisons were made using Duncan methods. The results showed the significant effects of incision on all the F. assafoetida traits (P<0.05). The effects of density and interactions of density by incision were not significant for all the traits. Results showed that the plants with a traditional incision had the lowest properties. It was concluded that the traditional incision method is fatal for plants and it is suggested to be replaced with 45-degree cutting method in plant density of 70´50 cm.