Growth and termination of cylindrical micelles with cholesteric liquid crystal (LC) cores (seeds) were achieved experimentally, following the simulation studies of liquid-crystallization-driven self-assembly (LCDSA) of block copolymers. The fluidity of LC cores was proven to be crucial for this success. To a seed solution, the added block copolymer unimers had a high tendency to form new aggregates. The formed aggregates had a less-ordered cholesteric LC structure as compared with those in the seed and subsequently fused with the seeds. After the fusion, the fluidity allowed a rearrangement of the rod blocks within the elongated segments to match the LC structure in the seeds. The fusion and rearrangement were repeated in cycles, which completely consumed the newly formed aggregates and led to a seeded-growth behavior. Under a condition that the interactions between LC blocks are stronger, the newly formed aggregates had smectic LC cores, which fused with the seeds terminating the growth. The termination is attributed to the higher energy barrier for the transition from the smectic LC structure to cholesteric active ends. This work created a theoretical basis for further exploration of living assembly using LC block copolymers, which are building blocks for a wide range of functional materials.