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We present a model atmosphere analysis of ten new DO white dwarfs and fivenew PG 1159 stars discovered in the Sloan Digital Sky Survey DR1, DR2 and DR3.This is a significant increase in the number of known DOs and PG 1159 stars. DOwhite dwarfs are situated on the white dwarf cooling sequence from the upperhot end Teff ~ 120 000 K down to the DB gap (Teff ~ 45 000 K). PG 1159 stars onthe other hand feature effective temperatures which exceed Teff = 65 000 K withan upper limit of Teff = 200 000 K and are the proposed precursors of DO whitedwarfs. Improved statistics are necessary to investigate the evolutionary linkbetween these two types of stars. From optical SDSS spectra effectivetemperatures, surface gravities and element abundances are determined by meansof non-LTE model atmospheres.Comment: 6 LaTeX pages, 5 PS figures, accepted for publication in Astronomy &  Astrophysics; fixed object name in Table 1 (third object from top) and minor  correction

Spectral analyses of DO white dwarfs and PG 1159 stars from the Sloan Digital Sky Survey