本文用微量星热法测定了在２９８．１５Ｋ时，α－氨基丙酸在纯水和卤化钾水溶液中的溶解焓，并求算了焓相互作用参数ｈ＿（ｘｙ）、ｈ＿（ｘｘｙ）和ｈ＿（ｘｙｙ）的值．根据理论推导了静电相互作用对ｈ＿（ｘｙ）值贡献的计算公式，并运用结构相互作用模型讨论了焓相互作用参数随电解质离子半径的变化规律． In this paper, the enthalpy of α-aminopropionic acid dissolved in pure water and potassium halide aqueous solution was measured at 298.15K by means of micro-calorimetry, and the enthalpic interaction parameters h xy, h xxy and h_ (Xyy) value. According to the theory, the formula of the contribution of electrostatic interaction to the value of hx (xy) is deduced and the change law of enthalpy interaction parameter with the ionic radius of electrolyte is discussed by the structural interaction model.