Waste leaves if not managed properly can cause environmental, social, and health problems. Processing waste into compost can provide additional economic value for farmers. The best current solution in waste management is to implement an integrated waste management system with composting techniques with the help of microbes. This research aims to determine the effect of bio-activator cow manure on the rate of leaf litter decomposition of various types and some related parameters change during the process of decomposition. This research used a completely randomized design (CRD) consisting of three treatments with three replications. The first treatment is PA (leaves of Samanea saman (Jacq) Merri rain tree. (1 kg) + 20% cow manure. The second treatment is PB (Pterocarpus indicus PC (leaf Mahogany Swietenia macrophyla King (1 kg) + 20% cow manure) is the final treatment. The parameters observed were color of compost, temperature, compost moisture content, pH, decomposition rate, and the ratio of C to N. The results showed bio-activator administration significantly affected the rate of decomposition in the NT treatment (0.46 gram/10 days), PA (0.51 gram/10 day) and PC (0.52 gram/10 days). Treatment PB and PC blackish brown colored black while the PA. PB treatment effect parameters are best for temperature (28.3 ° C), moisture content (36.06%) and pH (6.73). The PA treatment effect parameters are best for the C/N ratio (25.93%).