Abstract: ESR hollow cylindrical casting inner mold heat transfer coefficient α_○in is the core parameter to measure the effect of inner mold cooling. The range of α_○in was determined by inputting the measured values， including cooling surface temperature of the inner mold copper plate and water temperature， into basic formula and finite element analysis. The empirical formula for calculating α_in was determined by comparing with the empirical formula of heat transfer coefficient for annular casting. The experiential formula of α_○in explicates the effects of temperature difference， the short pipe effect and the shape factor of inner mold water model on α_in by using temperature difference function， effector and velocity function， which provides a theoretical basis for α_○in database establishment.

Key words: ESR hollow cylindrical casting, inner mold, heat transfer coefficient, water velocity, temperature