Abstract: This study analyzes changes in the demographic structure of population in Northeastern Montenegro in the example of the Municipality Berane, Andrijevica and Plav. Population age structure is changing and takes unfavorable characteristics, reduces the proportion of younger and increases the proportion of elderly population. Disturbed age structure has a reverse effect on the movement of the population (the size of reproductive contingent) but also, to all other population structure (size of contingent employment, population, mandatory school contingent, relationship maintenance). Despite significant changes in the demographic structures of all Northeastern Montenegro, retains the characteristics of ethnically very heterogeneous environment.