The purpose of this study was to determine the percentage value of motility and viability of spermatozoa in frozen semen Boer Goat by adding a combination of streptomycin with sweet orange essential oil to tris yolk extender. The material that will be used in this study are Boer Goat fresh semen, tris yolk extender, streptomycin and sweet orange essential oil. Tris yolk extender was prepared with Tris (hydroxymethylaminomethan) (3.32g), citric acid (1.86g), fructose (1.37g), glycerol (6ml), egg yolk (20ml), aquabides (100ml). The experimental design used in the study was a non factorial complete randomized design with 5 treatments and 5 replications. The treatment given is the addition of sweet orange essential oil 0%, 0.25%, 0.5%, 0.75% and 1%. The results showed that the addition of a combination of streptomycin and sweet orange essential oil to the extender had a very significant effect (P <0.01) on the motility and viability of Boer Goat spermatozoa before and after freezing. The best average value of motility and viability spermatozoa in the addition of essential oils is 1% (P4). Before freezing by 75% motility and viability 82% and after freezing by 50% motility and viability 67%.