Manganese oxides are promising anode materials for lithium ion batteries based on conversion reactions. In this paper, MnO nanoparticles that were embedded in a carbon matrix were directly produced by a facile glycine–nitrate-based solution combustion synthesis (SCS) process with subsequent calcination treatment under an inert atmosphere. The effect of the amount of glycine used in the SCS process and the calcination temperature on the composite products as well as their electrochemical properties were investigated. The carbon content in the composite can be controlled by changing the amount of glycine, while the crystallinity, and morphology of the MnO particles, phase composition, and the characteristics of the carbon materials were quite dependent on the calcination temperature. The sample calcined at 700 °C with a composite carbon content of around 27.7% provided the best electrochemical performance. This sample delivered a reversible specific capacity of 437.6 mA h g⁻¹ at a high current density of 500 mA g⁻¹ after 300 cycles. The enhanced electrochemical properties can be ascribed to the formation of a MnO nanoparticle/carbon composite. The carbon matrix offered a connected structure for fast Li ion and electron transportation, and worked as a buffer to accommodate the volume change upon lithium insertion/extraction.