A new configuration and operating method therefore improves conventional continuous pickling and cold-rolling systems in response to increasing demands for high-propertied steel plates. The continuous pickling and cold-rolling equipment system comprises a uncoiling apparatus, a joining apparatus, an accumulating looper, a cleaning section, a pickling section, a cold rolling mill, a cutting apparatus, and a coiling apparatus. This configuration and associated operation method realize a rolling line having a substantially infinite number of mill stands enabling continuous or endless cold rolling without additional mill stands. Thereby, production of cold rolled steel strip with a large total reduction ratio for high-grade steel strips effectively using a small number of mill stands becomes practicable. At least one of the embodiments clearly shows acceptable productivity that can stand comparison with a typical conventional cold rolling system.