A method for producing a modified conjugated diene-based polymer having a good balance between the hysteresis loss properties and the wet skid resistance, practically sufficient abrasion resistance and breaking strength, and high processability when formed into a vulcanized product is provided. A method for producing a modified conjugated diene-based polymer, comprising: a polymerization step of polymerizing a conjugated diene compound, copolymerizing conjugated diene compounds, or copolymerizing a conjugated diene compound with an aromatic vinyl compound using an alkali metal compound or an alkaline earth metal compound as a polymerization initiator to obtain a conjugated diene-based polymer having an active end, and a modifying step of reacting a compound represented by following formula (1) with the active end of the conjugated diene-based copolymer.