Embryotrophic factors from human oviductal cells were partially purified by liquid chromatographic methods. The conditioned medium from human oviductal cell culture was fractionated successively by concanavalin A (Con-A) affinity chromatography, ion-exchange chromatography and gel filtration. The presence of the embryotrophic activity in the eluates was determined by the stimulatory effects on the development of mouse embryos in vitro. The fraction that did not bind to the lectin Con-A possessed no embryotrophic activity. Ion-exchange chromatography separated the glycoproteins that bound to Con-A into five fractions. Three of them significantly enhanced blastulation as well as conceptus formation. Gel filtration further separated these embryotrophic fractions into five fractions. Three of them with molecular weights of 154 +/- 1, 164 +/- 0.2 and 207 +/- 0.3 kDa significantly stimulated blastulation of mouse embryos. The results of this study demonstrated that several embryotrophic factors with different biochemical properties contributed to the embryotrophic effect of the human oviductal cell/mouse embryo co-culture system.