With 3% O2 concentration, effects of different CO2 concentrations on fruit quality, post-harvest physiology and tissue browning of ‘Whangkeumbae’ were investigated by using accurate CA match air equipments during shelf-life days. The results showed that different treatments of controlled atmosphere (CA) could delay declining of fruit firmness. Furthermore, under the treatment at CO2 concentration of zero, the fruit respiration rate and polygalacturonase (PG) activity were obviously inhibited by CA and there were no browning reaction on the pericarp and pulp with high firmness and good flavor of fruit after 180 days storage. Under 0.5% CO2 concentration treatment, there was light pulp browning. According to the experiment, 3% O2 and CO2 concentration of 0~0.5% was optimal condition for CA storage of ‘Whangkeumbae’. ‘Whangkeumbae’ pear is sensitive to CO2. When CO2 concentration was more than 1% the fruit browning were more serious with increasing of concentration of CO2. The results also indicated that PPO activity and the content of ethanol were important factors of browning reaction in ‘Whangkeumbae’ pear. 