A valve for liquids includes a main body and an upper lid or a connector. The main body is provided with a flow passage, an annular connecting circumference, an opening surrounded by the annular connecting circumference, and at least a metal ring integrally wrapped in the annular connecting circumference. The upper lid or the connector is provided with an annular connecting circumference having at least one metal ring integrally wrapped in it. Therefore, after having the main body combined with the upper lid or the connector, the valve can withstand comparatively large fluid pressure so as to prolong service life and be used to a wider application.