Abstract: ObjectiveSeed morphological characteristics and the changes in seed germination process of four kinds of stylo were observed and analyzed to provide references for further study on seed characteristics , developmental mech-anism , embryo germination and stylo cross breeding . MethodFour kinds of stylo , including S. guianensis SW . cv . Reyan No.2, S. hamata(L.)Taub.cv. Verano, S. scabra Vog cv. Seca and S. hippocampoides Fine stem stylo were used to investigate embryo changes, germ and radicle length in the germination. ResultThe results showed that pod shape and coat color of seeds of four stylo varieties were different , but the processes of seed germination were basically the same, which could be divided into 5 morphological types. Different varieties varied in cotyledon color, germ growth time and plumule length. The cotyledon of Reyan No.2, Verano, Seca and S. hippocampoides Fine stem stylo expanded when buds grew to 5.7, 4.0, 4.0 and 3.2 centimeters, respectively. Germ of Verano stylo ran out on fifth day of seed germination, while the other three kinds of stylo on the fourth day. Except Seca stylo, the other three types had lateral roots. The bud length of Seca and Reyan No.2 stylo was longer than Verano Stylo , and Fine stem stylo was the short-est . ConclusionSeed pod , seed coat color and cotyledon color during the germination , germ growth time and plumule length are different among the four varieties of stylo. These differences can be used as research indicators for seed characteristics, seed development mechanism and embryo germination.