Abstract: The paper deals with features of pollen assemblages and their relationship to vegetation by comparing the results from surface pollen analysis with that from sample determination. It showed that Chenopodiaceae dominate with some Artemisia and a few Ephedra in steppe area. Although A/C (Artemisia/Chenopodiaceae) value was lower and more complicated than arid steppe area, it could reflect the humidity and the level of grass degeneration. The much more Pinus and Betula pollen percentage might be the main environmental noise source produced as statistical error. There were no obvious difference on pollen assemblage among the steppe types as Stipa gobica, S. krylovii, Peganum-Achnatherum except Artemisia and Chenopodiaceae pollen. However, there were some difference among meadow steppe, viz. sparse Ulmus pumila and Salisc tree, Aneurolepidium chinense and also the types like Salisc flavida, Stipa gobica, S. krylovii, Peganum-Achnatherum. Features of pollen assemblage in steppe degeneration and applications of PCA (principal component analysis) and method on surface pollen analysis were discussed.

Key words: Surface pollen analysis, Pollen assemblage, Principal component analysis, Environmental noise