Based on the study of the natural fire disturbance history at scale of landscape, this paper discusses the influences of long fire disturbance and last fire disturbance regime upon the biodiversity of shrub, herbivore and whole underlayer vegetation in virginal forest, northern Daxinganling Mountains, China. Six biodiversity indices are used in this paper, including one species richness index (i.e. number of species, S), two evenness index (i.e. Pielou evenness index Eh’ and Alatalo evenness index E) and three species diversity indices (i.e. Shannon-Wiener index H’, Hill indices N1 & N2). In general, the shrub layer shows higher values in species diversity indices than the herbivore layer does, which means that the shrub layer plays a more significant role in the plant diversity of the underlayer vegetation. Based on the ANOVA, the influences of fire disturbance upon the species richness and species diversity of the shrub, herbivore and whole underlayer are very significant, however, the effects on the evenness indices are not obvious. Influenced by the long fire disturbance, almost all the biodiversity indices show the following sequence: high frequency > middle frequency > low frequency, low severity > middle severity > high severity. However, under the effect of last fire disturbance, much of the biodiversity indices are that: low severity > middle severity > high severity, short duration > long duration > middle duration. The relation between the underlayer biodiversity of plant community and the fire disturbance is resulted from the long adaptation. Under the influence of fire disturbance with low-frequency & high-intensity, a lot of the on-site plants are destroyed while it is difficult for other plants to colonize. This results in a poor status in species diversity. However, a lot of on-site plants can recover and even survive from the fire disturbance with high-frequency & low-intensity, and much more other plants can invade into the site too, which leads to the higher values in plant diversity.