In this paper, the main aim is to discuss the existence of the extreme points and support points of families of harmonic Bloch mappings and little harmonic Bloch mappings. First, in terms of the Bloch unit-valued set, we prove a necessary condition for a harmonic Bloch mapping (resp. a little harmonic Bloch mapping) to be an extreme point of the unit ball of the normalized harmonic Bloch spaces (resp. the normalized little harmonic Bloch spaces) in the unit disk 𝔻. Then we show that a harmonic Bloch mapping f is a support point of the unit ball of the normalized harmonic Bloch spaces in 𝔻 if and only if the Bloch unit-valued set of f is not empty. We also give a characterization for the support points of the unit ball of the harmonic Bloch spaces in 𝔻.

本文的主要目的是讨论调和Bloch映射族和小调和Bloch映射族的极值点和支持点的存在性。首先，对于 Bloch 单位值集，我们证明了调和 Bloch 映射（或小调和 Bloch 映射）是归一化调和 Bloch 空间（或单位盘𝔻中的归一化小调和布洛赫空间）。然后我们证明调和 Bloch 映射f是 𝔻 中归一化调和 Bloch 空间的单位球的支持点，当且仅当f的 Bloch 单位值集不为空。我们还对 𝔻 中调和 Bloch 空间的单位球的支撑点进行了表征。