To understand the VA status, the detectable rate of the sub-clinical VA deficiency and the correlation of VA and iron in the rural school-age children of Beijing Mountain Area. In the dietary survey, blood samples were collected by venopunction and serum VA, and hematological index were determined in 305 children 7-13 years. The intakes of dietary energy, protein and iron were > 85% of the RNI and AI, but dietary intake of VA were (513.7 +/- 286.1) microgram to be 59.7% of the RNI; The average concentration of serum VA was (1.01 +/- 0.29) mumol/L, 59.0% of subjects have serum VA lower than 1.05 mumol/L, in which, 12.8% of them were lower than 0.70 mumol/L, and only 41.0% of subjects were normal levels of serum. With aggravation of iron deficiency from ID to IDA phase, the average serum VA concentrations were descending from 1.02 mumol/L in ID phase to 0.97 mumol/L in IDA phase. But the trend has no statistical significance. The results showed that sub-clinical VA deficiency was 59.0% in the rural school-age children, so VA deficiency was a main nutritional problem in rural school-age children of Beijing mountain area.