Abstract: With the feature of high seepage area and low flow resistance, horizontal?well technology has been widely applied to the development of oil and gas fields in our country due to its high productivity. Meanwhile, various kinds of production rate formulas are often used to evaluate the productivity of horizontal wells. The main production rate formulas for horizontal wells which have been valued and applied in our country include: Borisov formula, Joshi formula, Giger?Resis?Jourdan formula, Renader?Dupuy formula and Chen Yuanqian formula. At present, these formulas are not used effectively because the difference and uncertainty of these formulas have not been enough mastered. In this paper, some comparisons of these formulas were studied, and some evaluation methods were also proposed, including productivity index, equivalent flow resistance, skin factor, heterogeneity and eccentricity, etc