On a support, the thermosensitive containing subbing layer containing as main components a pigment and a binder, and a developer for coloring by reacting with colorless or pale colored basic colorless dye and said basic colorless dye as a main component in thermosensitive recording medium having a recording layer, undercoat layer contains a water retention agent, (based on JIS K 5101 method) oil absorption of the pigment contained pigment 80cc / 100g~120cc / 100g, further undercoating layer coating solution solids concentration dynamic water retention value of at 25% to 45% of (AA dehydration amount) by at 350 g / ^{m 2} or less, to provide good heat-sensitive recording material quality.