Liquid–liquid phase separation (LLPS) has emerged as a new paradigm in the fields of soft matter, colloid chemistry, prebiotic chemistry, and cell biology. As phase separation is a dynamic assembly process, how to spatiotemporally regulate the assembly and disassembly of these micrometre-sized droplets, which are referred as biomolecular condensates in biology is essential for their diverse applications in various disciplines. Herein, we discuss recent advances in the spatiotemporal control of phase separation using different physical tools and external environmental stimuli in bulk solutions and living cells. Specifically, the exploration of phase transition in a compartmentalized protocellular system, which can bridge the gap between synthetic and intracellular LLPS systems, is summarized, and the challenges and future research directions are discussed.

液相-液相分离（LLPS）已成为软物质，胶体化学，益生元化学和细胞生物学领域的新范例。由于相分离是一个动态的组装过程，因此如何在时空上调节这些微米级液滴的组装和拆卸，这些液滴在生物学中被称为生物分子缩合物，对于它们在各个学科中的多样化应用至关重要。在本文中，我们讨论了在体积溶液和活细胞中使用不同的物理工具和外部环境刺激进行相分离时空控制的最新进展。具体而言，总结了在分隔的原生细胞系统中可以弥合合成和细胞内LLPS系统之间的鸿沟的相变探索，