A method of producing a resin sheet, including: mixing blocky boron nitride particles A, blocky boron nitride particles B, and a resin composition, and molding the resin composition to a sheet form and pressurizing the sheet form resin composition, the boron nitride primary particles a having a length in a shorter direction of 0.7 μm or less, the boron nitride primary particles b having a length in a shorter direction of 1 μm or more, the blocky boron nitride particles A having an average particle diameter of 30 μm or more, the blocky boron nitride particles B having an average particle diameter that is smaller than the average particle diameter of the blocky boron nitride particles A, the compressive strengths ratio of the blocky boron nitride particles A to the blocky boron nitride particles B being 1.2 or more. Thus, the thermal conductivity of a resin sheet can be enhanced.