Abstract: A thermal sensitive recording medium which further contains poly urea compound in the thermal color developing layer containing dye precursor and color developer, which displays an excellent image preservative stability. Said poly urea compound contains units of a structure represented by general formula (1), and further contains a repeating unit represented by general formulae (2).about.(7). ##STR1## In these formulae A.sup.1 .about.A.sup.7 are a divalent group, R.sup.1 .about.R.sup.5 are an alkyl group, an alkoxy group or an electron accepting group, o, p, and q are an integer from 0 to 4, r is an integer from 2 to 12 and s and t are an integer from 0 to 8.