One kind of the popular Thai salad is named Som-Tam which has shredded unripe papaya as main ingredient. For self-cooking, the process for making the shreds is complicated. Ready-to-use form as shredded unripe papaya would be necessary for the consumer. However, this product will deteriorate quickly after processing when subjected to the normal air condition at ambient temperature. In this research, the postharvest controlled atmosphere technique was applied to study the effect on sensory attributes decay of shredded unripe papaya under normal air (control), 5% O 2 , 10% CO 2 and 5% O 2 +10% CO 2 conditions, respectively, during storage at 4°C. The sensory attributes (color, off-odor, water soaking, chilling symptom and crispness) of each sample was tested throughout storage time in 5-day intervals using a five-point scale (1-5 score). A kinetic model for fitting sensory attributes changes was applied. The water soaking and chilling symptom slightly changed in all treatments. The scores of color, off-odor and crispness decreased with time especially in control. The results showed that the limiting attribute factor was the internal quality (crispness of shreds). The combined low O 2 and high CO 2 condition showed the best treatment to retain the quality change of shredded unripe papaya.