Abstract: This paper is largely dealing with the recent on-the-spot investigation and palynological study on yellow rain in northern Jiangsu Province. Many samples of yellow rain on leaves of lettuce (Lactuca sativa L.) collected from the village of Xinxi, southwest of the township of Xinfeng, Jingjiang County were analyzed using palynological technique. The yellow drops were composed mainly of pollen from crops which are common in the area and they were in blossom at that time. Among the grains observed in acetolysed preparations the dominant element is the oil-bearing crop pollen of Brassica campestris L. (69.7%, 634 grains counted), plus some other pollen such as Vicia faba L. (27.1%) and Astragalus sinicus L. (1.4%). On investigation it was found out that there did exist an apiary around the yellow rain site. The bee feces, however, bore a strong resemblance both in appearance and in pollen compositioa to the yellow spots on leaves we collected. Palynological analysis showed that samples of yellow rain collected from different times at the same site were completely different in their pollen composition, suggesting that the local flowering plants are the source of the pollen found in samples of yellow rain. All data obtained so far do support the bee feces theory for the origin of yellow rain proposed by one of the authors (Zhang Zhong-ying) early in 1977, indicating that yellow rain is a phenomenon of nature.

Key words: Yellow rain, Pollen, Bee feces theory