Abstract: Background and Objective: In Indonesia, most of the population relies on rice as their main staple food; however, the production of rice is dependent on inorganic fertilizers which not only increase cost production but also decrease soil fertility and pollutes the environment. Therefore, the development of organic fertilizers derived from natural resources which are more affordable with high bioavailability has recently become an important study. This study aimed to evaluate the effects of solid and liquid macroalgae extract on growth and yield of rice plants. Materials and Methods: The treatments consist of solid, liquid extract of brown macroalgae, such as Sargasum crassifolium, Sargasum cristaefolium, Sargasum aquifolium and Turbinaria murayana, combined solid form of all algae species and combined liquid form of all algae species. Treatments were conducted in 8 weeks, followed by measurements of vegetative growth and yield of rice plants. Results: The results show that solid and liquid extracts have different efficacy on growth and yield of rice plants. Application of macroalgae solid fertilizer increased vegetative growth; such as number of leaves and tillers in rice plants compared to liquid fertilizer treatments. Interestingly, macroalgae liquid fertilizer proved to be more effective in promoting yield based on shoot/root (S/R) ratio. However, 1000 seed weight of rice plants were not affected by fertilizer treatments. Conclusion: Nevertheless, current study provides effectiveness of macroalgae liquid fertilizer compared to solid fertilizers. Further evaluation of macroalgae fertilizer mechanism in promoting growth and yield of rice plants would be necessary for utilization in various agricultural industries.