Abstract: The sedimentary veins of Tamarix cone is a new method to recovery the ancient environment. On the basis of the positive ion content and the relationship between the content of K+,Na+,Ca2+ and Mg2+ in the layers of the fallen leaves in sedimentary veins of Tamarixcone and environmental change in Lop Nur region，the researched result has been obtained as follows: the average positive ion contents of K+,Na+,Ca2+,and Mg2+ are 3.70 mg/g,40.33 mg/g,13.67 mg/g and 8.08 mg/g respectively,the order of their change range is Ca2+>K+>Mg2+>Na+; The interannual changes of the four kinds of metal element content are more obvious,and the variation trend is more consistent,the correlations between each metal element contents are positive correlations with correlation coefficient of 0.653 0-0.813 8; The correlation coefficients between the total positive ion content and the each one are 0.814 4-0.959 9,the correlation coefficient between Na+ content and the total positive ion content is the highest,which indicating that Na+ content or the total positive ion content can reflect the change trends; there are better positive correlation between the content of positive ion and air temperature,and an inverse correlation between the content of positive ion content and annual precipitation and lake water surface area; with the underground water level has been downing,the water quality of underground water has become worse,and the quality of soil water has become worse,the content of positive ion has increased; conversely with the underground water level has been going up,the water quality of underground water has become better,and the quality of soil water has become worse,the content of positive ion has decreased. The change of positive ion content in organic materials of Tamarix fallen leaves has verified the reliability of the dating of sedimentary veins of Tamarix cone,and the feasibility of using sedimentary veins of Tamarix cone to reveal the environmental change in Lop Nur region.