The „Codrii” Reserve was created in 1971 in order to conserve the most representative areas with the pedunculate oak, sessile oak and beech forest of Central European type. The territory covered by forest constitutes 5040.7 ha. Up to founding the reserve, the forest stands were managed intensively in regime of thicket with the regeneration of shoots. This mode of management focused only on getting timber and inevitably led to the substitution of the oak forest with mixing species (ash, lime, cherry, hornbeam, maple). As a result, there are 26.1% (131 6 ha) fundamental natural forest stands, 1.6% (79.3 ha) degraded forest stands, 64.3% (3242.6 ha) derived forest stands and partially derived and 8% (402.8 ha) artificial forest stands. Of the total area represented by forest, only 547.1 ha (11%) are permanent forest stands (generative) with a high eco-protective capacity, but 89% are classified as inappropriate forest stands, in which the ecological reconstruction works are to be conducted. As a result of researches in the field and according to Management plan of reserve (2010), were highlighted 244 subplots with structural inappropriate stands that require ecological reconstruction. The stands regeneration with the main species that existed before being degraded or structurally damaged is at the base of carrying out of the ecological restoration. In 2012, on seven subplots, were delimited sample surfaces (54M; 2A; 3B; 14K; 12G; 35B and 35J) in inappropriate stands. The delimitation of sample surfaces aims at studying the unfolding of ecological reconstruction process by applying appropriate treatments and the regeneration peculiarities. In each sample surface, the inventory of forest vegetation was performed, the current composition of stand, the soil type, the station and forest type were established, to determine the correspondence with data from forest planning and were applied the appropriate treatments for each sample surface separately. It was analyzed the unfolding of ecological reconstruction on two sample surfaces: 54M - partially derived stand and 35J - totally derived stand. The partially derived stand (54M) has undergone the treatment of progressive cutting after that resorted to treatment of combined cutting (progressive and successive). The regeneration occurred naturally with soil mobilization. In the area where the acorns have not penetrated into the soil by mobilization, it was intervened with sowing the acorns. In the totally derived stands (35J), it was applied the successive cutting treatment in two stages and sown the pedunculate oak acorns in rows with distance of 3 m. In both sample surfaces, it was carried out the cutting of offshoots and suckers to prevent overwhelming of the seedlings. According to technical standards developed by the Agency "Moldsilva", the result of the natural regenerations is considered very good when we have per 1ha 13000 seedlings of sessile oak or 10500 of pedunculate oak, whereas in our case in p. 54M we have 230000 seedlings of sessile oak, 20000 – pedunculate oak, 90000 – hornbeam, maple and linden with 10,000 each, but in p. 35J were registered 22440 seedlings of pedunculate oak, which we consider very good results for ecological restoration.