| Based upon a progressively revised empirical model, the microclimate observation data was analyzed between October and May from 2008 to 2011 in the cucumber sunlight greenhouse, located in Gaoyi county, southern central Hebei Province. Potential productivity by photosynthesis and light-temperature in greenhouse had been estimated. The results showed that photosynthetic potential productivity values in the greenhouse of one crop period were 63 803.7～130 556.2 kg·hm-2, which was higher in general years and lower in overcast days. When photosynthetic potential productivity value was very low, the greenhouse production would be at risk. Light-temperature potential productivity values in the Greenhouse of one crop were 54 691.1～59 683.9 kg·hm-2. The average temperature correction coefficient was at least 0.8, meaning that the restriction of temperature on photosynthetic potential productivity was not obvious. The photosynthesis potential productivity during the whole crop period reached most in May and least in February. The light-temperature potential productivity was highest in May and lowest in January. When optimal light and temperature conditions could be satisfied, the actual yield of cucumber in greenhouse had reached 17.9% of the potential yield, suggesting that great potential in increasing cucumber yield yet remained to be fulfilled. |