The purpose of this study was to obtain red onion extract that is appropriate for the growth of crystal guava stem cuttings. This research was conducted at Greenhouse San's Garden Jl. Kaliurang km 16, Kledokan, Umbulmartani, Ngemplak, Sleman, Yogyakarta Special Region and Research Laboratory of Muhammadiyah Yogyakarta University in July to October 2018. The research method used was an experimental single factor arranged in a Completely Randomized Design (CRD). The treatments tested were without concentration, fresh onion extract concentration of 1%, macerated red onion concentration of 1%, 2%, 3%, IBA with a concentration of 500 ppm. The results showed that the concentration of 2% macerated red extract was able to grow roots and shoots with the same criteria and could support IBA concentrations of 500 ppm in crystal guava stem cuttings.