This study investigates the molecular,carbon,and hydrogen isotope compositions of n-alkanes in eight pairs of a holoparasitic plant (Cuscuta chinensis) and its hosts.It is unexpected that C.chinensis has a higher concentration of n-alkanes than its hosts in seven of the eight pairs,and it is preferentially dominated by n-C29 alkane (representing＞ 75％ of the total n-alkanes).In addition,the δ13C values of C29 alkane in C.chinensis are less negative (avg.1.8 ‰) than those in the hosts,while the δ2H values ofC29 alkane are more negative in C.chinensis (the difference averages 48 ‰).We propose that the 2H-depletion of n-alkanes in the stem parasite C.chinensis may result from the utilization of stem water with less influence from evapotranspiration or the use of newly synthesized carbohydrates which is 2H-depleted relative to stored sugars.These results highlight the importance of plant nutrient status on the molecular and isotopic compositions of leaf waxes,which shed light on the (paleo)ecological potential of leaf wax δ2H values.