Pea membranes were incubated with UDP-[14C]galactose and sequentially extracted with lipid solvents and 2% sodium dodecyl sulfate (SDS). At least 3/4 of the products were SDS-soluble. All fractions contained some [14C]glucose, indicating the presence of an active epimerase which, however, could be inhibited by ADP-ribose. The chloroform-methanol extract contained mainly neutral galactosyl lipids and a small amount of dolicyl monophosphoryl glucose. The chloroform-methanol-water extract contained trace amounts of lipid-linked galactosyl oligosaccharide with properties comparable to polyisoprenyl pyrophosphoryl derivatives. Polyacrylamide gel electrophoresis of SDS-soluble products indicated the formation of both immobile and mobile components with similar size distribution (Sepharose CL-6B). The mobile component only was susceptible to hydrolysis by protease. Periodate oxidation analysis of SDS-soluble and -insoluble products indicated that they were composed mainly of 1 .fwdarw. 6 galactosyl residues, i.e., as in many arabinogalactan proteins and arabinogalactans.