Greenhouse have been developed to provide the plants with good environmental conditions for cultivation crop. One of the biggest challenges for greenhouse owners is to properly coordinate the cooling and heating systems to avoid economic loss. Without a method of removing excess heat, the temperature may increase to levels detrimental for crop growth. Ventilation is one of the most important actions in greenhouse cultivation because greenhouse inside temperature rapidly rises in warm climates. Ventilator in multi-span greenhouses is controlled by a proportional algorithm. The relationship between temperature changes in the greenhouse and ventilation is not linear. Conventional strategy of ventilation mostly employs a proportional band (PB) control, which contains various settings relating to the solar radiation, outside temperature and wind velocity In practice, these settings may have a relationship with the set ventilation temperature. However, it is difficult to find optimized settings because the settings must be changed according to the greenhouse location, shape, or local climatic conditions. In this study, a method to optimize the P-band parameters for external temperature, solar radiation, and wind speed affecting greenhouse ventilation was conducted by surface response analysis. The surface response analysis was used to confirm the quadratic response of the relationship between X and Y, which was designed using the central composite design. A total of 32 experimental factors were designed and the results were analyzed by empirical tests. In addition, derivative calculations were added to respond to rapid changes of temperatures in the greenhouse and used for ventilation parameters. The results showed that optimized parameter successfully applied in temperature control and obtained the better performance with an RMS error of ± 0.919°C.