Visits from landscape of different cities of Khorasan-Razavi province, including Kashmar, Torbat-Heydarieh,Torbat-jam, Neishaboor and Mashhad Showed that one of the important issues of plant protection in pine trees is the tip blight.The symptoms of this disease have increased noticeably over the past three years.The disease begins with a discoloration of the needles at the tips of pine branches, gradually the needle leaves are brown and completely dry. The infected needles is stunted and appears to be smaller than healthy needles. In progressive stages of this disease, infected twigs also are stunted. This disease gradually weakens the tree and can lead to complete plant death. The most important characteristic of the disease is the presence of black and small fungal fruiting bodies at the base of the needle leaves,under the paper leaf sheaths and sometimes on cone scales.Isolation and purification of the fungus from the infected plant tissues, investigation on macroscopic characters including the colony shape and color, microscopic traits including the color, shape and size of the conidium,conidiogenus cells and Pycnidium also pathogenicity test that led to the diagnosis of Diplodia sapinea as pine tree tip blight causal agent. In the next section of this study Iprodione + carbendazim (Rovral TS) 52.5% WP, Thiophanate-methyl (Topspin M) 70% WP, Propiconazole (Tilt) EC 25% and Tebuconazole (Folicur) 25% EW, Each of the three concentrations is evaluated in terms of the effect on the growth reduction of the pathogen in the laboratory. The results of this study showed that all tested fungicides were effective in reducing the growth of the pathogen,However, this effect was different depending on the type of fungicide and the concentration.The results showed that Iprodione+ carbodaziim, Tiophanate methyl, Propiconazole and Tebulconazole with concentrations of 15, 25, 60 and 75 ppm respectively stopped the pathogen's growth in the lab.