To develop commercial semi-solid apple baby food, the physicochemical characteristics of apple puree in relation to different preparing methods and the effect of the addition methods of ascorbic acid on browning reaction were investigated. The preparing methods were classified into 3 groups by initial heating treatment: no heating (A), steaming at $120^{circ}C$ (B), and blancing at $100^{circ}C$ (C). The viscosity of tested apple puree was $2,600{sim}5,856;cp$, and contents of anhydrogalaturonic acid (AGA) and neutral sugar ranged $4.15{sim}11.92;mg%$ and $6.18{sim}10.65;mg%$, respectively. Among free sugars tested, level of fructose was the highest $(5.43{sim}8.87%)$, followed by glucose $(2.11{sim}4.23%)$, sucrose $(1.64{sim}2.94%)$, in that order. Since small amounts of ascorbic acid were detected $(1.54{sim}1.83;mg%)$, it seemed to be lost by heating process in preparing of apple puree. For apple puree A, its lightness was lower and redness was higher than those of apple puree B and C. Its degree of browning of apple puree was so high that sodium ascorbic acid was added as a antibrowning agent. Puree had low sensory score and nutrient quality. The adding methods of ascorbic acid were classified into 4 groups by adding time: dipping, blending (2), heating (3), and blending + heating (4). Considering color and preference evaluation, preparing method B and adding method 2 showed the highest inhibitory activity on apple puree browning and desirable color for retort baby food. After retort sterilization, the viscosity of apple baby food was decreased from 3,477 cp to 2,294 cp, thiamin was destroyed completely, and the contents of riboflavin and ascorbic acid were decreased 41% and 21%, respectively. However, contents of free sugar and free amino acid and sensory parameter were not influenced by retort sterilization. In overall, the preparing method B-adding method 2 was a good processing condition for the retort apple baby food.