In this paper, some properties of domain tree languages of top-down pushdown tree transducers (domain(t-PDTT) or t-PDTTD) are shown. It is shown that (1) for any L1, L2 in context-free language (CFL), L1L2yielde(t-PDTTD) (where yielde is an extended yield), (2) yielde(t-PDTTε0DF) is closed under homomorphisms, where t-PDTTε0 is a t-PDTT which can not proceed generations after reading a constant symbol σ and t-PDTTε0DF denotes a domain tree language of t-PDTTε0 with a final state translation, and (3) yielde(t-PDTTε0DF) is the class of recursively enumerable languages, and consequently yielde(t-PDTTD) is the class of recursively enumerable languages.