The study on the biomass allocation and stoichiometric ratio of desert plants in different growth periods can help to?deeply understand nutrient cycling and limiting conditions of Guerbantongut Desert plants in extreme environment. In this study, four ephemeral plants, (Hyalea pulchella (Ledeb.) C. Koch), (Nonea caspica (Willd.) G. Don.), (Erodium oxyrrhynchum M.B.), (Lactuca undulata Ledeb.) were selected. The results showed that: (1) The biomass distribution of the four desert plants showed a consistent growth law during the whole growth cycle, while root-shoot ratio (R/S) showed a decreasing trend. However, the biomass accumulation rate was not the same in each growing period, but the final distribution ratio of the four plants converged with the completion of life cycle. (2) The C elements of the four plants remained high throughout the growth cycle, and the N and P elements in the plants showed an overall downward trend. As for the metrology ratio analysis, there is a positive correlation between C:N and C:P, but both are negatively correlated with N:P, while the results of N:P study are lower than the average of all xerophytes. (3) Comprehensive ranking of biomass and stoichiometric ratio showed that the degree of explanation of the first and second axes was 58.89% and 19.43% respectively, and 78.32% of the total information could be explained cumulatively, indicating a high credibility. But weak correlation between overall index, illustrates the four desert ephemeral plants grow in the process of stoichiometric ratio did not decide on the biomass allocation, plants may be due to the drought environment caused by the different survival strategy results or biomass allocation of the main factors of plants could be decided what their own genetics.