A ceramic honeycomb structure comprising pluralities of honeycomb segments each having pluralities of longitudinally penetrating flow paths partitioned by porous cell walls and plugs formed in the end portions of the flow paths, and a bonding material layer boding the peripheral walls of the honeycomb segments, the bonding material layer comprising silicon carbide particles as aggregate and a bonding phase bonding the silicon carbide particles, the bonding phase comprising at least a cordierite phase and a spinel phase, the molar ratio M1 of the cordierite phase [=cordierite phase/(cordierite phase+spinel phase)] being 0.50 or more and less than 1.0, and the content of (cordierite phase+spinel phase) in the bonding phase being 50% or more by mass.

A honeycomb structure includes a plurality of cell channels passing through an inside of the honeycomb structure and partitioned by porous partition walls, wherein the honeycomb structure includes 80.0 to 94.0% by mass of cordierite as a main crystalline phase and ceria contained in a secondary crystalline phase; the porous partition walls have a porosity of 60% or more as measured by a mercury porosimetry; and for the porous partition walls, a cumulative 10% pore diameter (D10), a cumulative 50% pore diameter (D50) and a cumulative 90% pore diameter (D90) from a small pore side satisfy a relationship (D90D10)/D501.2, in a volume-based cumulative pore diameter distribution as measured by the mercury porosimetry.