This Recommendation specifies the protocols of the algorithm-training system (ATS) for intelligent video surveillance (IVS), which meets the requirements, functional architecture, and reference points of ATS specified in [ITU-T F.743.22]. The performance of intelligent algorithms affects the intelligence level of IVS systems. The IVS systems deployed in various industry service scenarios can obtain massive visual data. The ATS continuously deploys the iterative algorithms generated by algorithm-training based on visual data to the IVS systems, which can enhance the analysis, computing, and inference capabilities of the IVS systems. This Recommendation is intended to guide the design, development, implementation, and application of ATS for IVS.