Four different greenhouse models were planned and tried on late autumn season. Greenhouses had both different ventilation gaps and different blanket materials. Effects, of different type of greenhouses on inside conditions of greenhouses (temperature, light, humidity etc.) were Investigated. In order to reach this aim, termohigrografs were settled into the greenhouses. Moreover humidity, light and temperature measurements were taken from six different points of greenhouses. Differences between covered material by normal plastic and antifog plastic for environmental conditions of greenhouses were worked. According to results, inside of the greenhouses werefound statistically significant depents on gap ventilation. All greenhouses were appraised relative to ventilation gap and it is established that difference among greenhouses were statistically significant. As a result of this, the most suitable ventilation gaps in the greenhouses which have ventilation gaps on the roof and side. Greenhouses which have ventilation gaps only on the roof had followed this type of greenhouses.