Our research was part of a broader study that deals with the carbon cycling in abandoned karstic pastures of Slovenian sub-mediterranean region (Podgorski kras, SV). At this site two study plots that differ in succession (pasture andgrassland invaded by woody plants) are researched. The aim of our work wasto make estimation of woody plants biomass at invaded area. The method for the field measurements of biomass was one proposed by Terrestrial Carbon Observation panel (TCO) of, the Global Terrestrial Observing System programme (GTOS) (http://www.fao.org/gtos/). We did an inventory and we calculate total woody biomass for each species with different allometric equation. Total woody biomass of the site was estimated to 32,065 t , and was mainly contributed by pubescent oak (Quercus pubescens L., 86 % of total). We did also a dendrocronological measurement, we took samples from 14 trees with a increment borer and we also collected disks from 4 trees. In 52 years the forest overgrowth 21% of dry karstic pastures we can see that in ours samples trees, we observe a significant growth in these years analizing our samples trees. None of the trees in our case culminate and biomass production is in all trees in exponential increase that culmination is reached at very high ages so basically carbon storage is constantly increasing. The information on diameter increment and growth patterns of trees contributes to understand the changes in carbon stock during woody plant encroachment.