A Global warming, climate change and negative human activities are expected to directly and negatively influence Mongolia’s forest resource area and quality [21]. In 2015, Mongolian forested area was 12,188.2 thousand hectare and in compared with the forested area in 2010, it has decreased by 864.5 thousand hectare. The important causes of deforestation and forest degradation are fire, improper commercial logging, illegal collection of wood for construction and fuel wood, overgrazing, mining activity, and damage by pests and diseases. Mongolian forest stand is not only decreasing in quantity, but also forest age class has been changing into maturity forest classification in recent years. The maturity forest resource has counted for 74 percent of total forest resource is in National Forest Inventory, 2016. There are few study for Mongolian forest stand dynamics and this work is first research that used stochastic process to predict forest stand dynamics in Mongolian case. This paper considered the main factors such as Climate factors and Socio-Economic factors in predicting forest stand dynamics. The factors are chosen based on real situation of forest resource’s changes in Mongolia. The study has estimated coefficients of relationship between forest resource and main factors, as well as main factors and their explanatory variables, using suitable regression model for all estimation. Moreover, Markov chain process has been used to extracted future dynamic of forest stand by age class structure based on imbalanced age structure of total forest resource today. The result of this paper shows that the most important factors that influenced the future forest stand changes are forest fire, commercial logging and afforestation. The estimated model results shows the forest fire will be decreased (9%), commercial logging will be increased (25%) and reforestation will be increased (30%) by 2030. Specially, this paper presented that forest resource will be decreased by 13 percent in future 15 years. Additionally, this decrease is consist of forest age structure changes which is young aged forest would be increased by 27%, middle aged forest would be decreased by 15%, maturing forest would be decreased by 39% and maturity forest would be decreased by 16% in 2030.