A Riesz space E is said to have the b-property if each subset that is order bounded in the bidual remains to be order bounded in E. Properties of a Riesz space with the bproperty, the relationship between the b-property and various classes of operators are studied.Keywords b-property · b-weakly compact operator · Strongly order bounded operator · Preregular operator Mathematics Subject Classification (2000) 46A40 · 46B40 · 47B60 · 47B65