Itisgenerallyacceptedthatthecompositionsandpropertiesofsoilorganicmatter（SOM）arein?uencedbymanyfactors.InordertorevealtheeffectsofsoiltextureoncharacteristicsanddynamicsofSOManditssub-fraction,humicacid（HA）,alongtwosoilpro?les,ayellowsoilpro?leandapurplishsoilpro?le,underthesameclimateandvegetationconditionsweredetermined.Resultsindicatethatthedecompositionandhumi?cationdegreesofSOMandHAofthepurplishsoilsarehigherthanthoseofthecorrespondingyellowsoilsindicatedbyA/O–AratiosofHAs,TOCsandHAyieldsofbulksoilsamples,nevertheless,thedevelopmentdegreeofthepurplishsoilislowerthanthatoftheyellowsoil.ThevariationsofE4/E6ratiosofHAsalongthesoilpro?lesindicatetheoverallmolecularsizesofHAsdecreaseddownwardalongthesoilpro?les.A/O–AratiosofHAsdecreaseddownwardalongboththesoilpro?lesindicatethathumi?cationprocessesdecreasedownwardalongboththesoilpro?les.LeachingofSOMshowssigni?canteffectsonthedistributionandcharacteristicsofHAsintheyellowsoilpro?lebutthepurplishsoilpro?le,whichisconsistentwiththehigherhydrophobicityofHAsinpurplishsoils,showsthatthedistributioncharacteristicsofSOMalongthesoilpro?lesareacomplexresultofthecombinationofsoiltextureandcharacteristicsofSOMitself.TheremarkablydifferentsandcontentsareconcludedtentativelyasoneofreasonstothedifferentdistributionsanddynamicsofHAsalongthesoilpro?les,however,toprofoundlyunderstandtheevolutionandtransportofSOMalongsoilpro?lesneedsmoreresearches.
