Excessive consumption of chemical pesticides in order to supply human daily nutritional requirements has been caused harmful problems to humans and environment. Accordingly, finding biodegradable and low-risk material as perfect alternative instead of chemical pesticides can solve these problems. One of the suggested solutions in this field is using of essential oils to control agents of plant diseases. Effective use of essential oils, because of the lack of sustainability in the field, has always been difficult. To investigate the increase of essential oils retention in the environment, mesoporous silica Nano-polymer used to formulate the Fennel (Foeniculum vulgare) essential oil, in this study. Then controlled release and its ability to control of the plant pathogen assessed. Fennel essential oil extracted with water distillation method using Clevenger apparatus. Its minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) measured against Pectobacterium carotovorum as one of the important plant pathogenic bacteria. 100 mg polymer added to 15% concentration of essential oil in distilled water. The obtained suspension placed on a magnetic stirrer in laboratory temperature for 17 hours. Formulated essential oil in Nano silica, precipitated by centrifugation and dried in laboratory temperature.formulation performance in essential oil storage, controlled release and its controller’s ability, investigated during specified time intervals in a period of several month .The results showed with increasing the humidity in the environment and water absorption, release of essential oil that was enclosed within Nano polymer, started and as soon as reduce the moisture content, decreased. The durability of essential oil that was enclosed within Nano polymer by virtue of having controlled release properties increase from 24 to 120 hours and thus durability of essential oil and its controller’s ability in the environment became desirable. So the use of polymers in the formulation could be effective measures to use of plant essential oils.