Seaweed Kappaphycus striatus is a potential marine biological resource in Indonesia, but the cultivation uses still the conventional method (long line). The decline in production yields is affected by environmental disturbances, such as pest attacks and release due to strong currents and waves, which are also not environmentally friendly. Therefore, it is necessary to develop new cultivation methods to increase seaweed productivity. This study aims to analyze the productivity of seaweed using Kajarula (Kantong Jaring Rumput Laut, also known as seaweed net bag) technology at Tablolong Beach, West Kupang, East Nusa Tenggara. The research design used for observation data was randomized pretest-posttest Control Group Design. Next, this research is a case study that includes interviews, observations, and following the process of production of seaweed using Kajarula technology. The production performance of seaweed cultivated for 42 days resulted in biomass production of 7.54 ± 0.27 kg/units with an average relative growth of 153.41 ± 10.97 %/day, a growth rate of 239.32 ± 21.95 g/day, and a total harvest of 5.82 – 7.45 kg/units. The water quality conditions in these waters are within the optimal range to support seaweed growth. The productivity of seaweed cultivation using Kajarula technology shows optimal growth and yields.