Developer for replenishment and image forming method

An image forming method employing a two component development method comprising at least:

• performing development;
• replenishing a developer for replenishment to a developing unit;
• and
• discharging at least an excessive magnetic carrier in the developing unit from the developing unit,
• wherein:
• the developer for replenishment comprises at least a toner and a magnetic carrier, and in the developer for replenishment, 1 part by mass of the magnetic carrier is blended with 2 to 50 parts by mass of the toner;
• and
• the magnetic carrier
• (i) contains a ferrite core which has a porous structure, and a resin component,
• (ii) has a true specific gravity of 2.5 to 4.2 g/cm3,
• (iii) has a 50% particle diameter on a volume basis (D50) of 15 to 70 μm, and
• (iv) has an average circularity of 0.850 to 0.950, the average circularity having a coefficient of variation of 1.0 to 10.0%.