Objective To investigate the effective way to test 4-year-old children's ability of sound localization in the horizontal plane. Methods Using minimum audible angle(MAA)measure procedure on the basis of conditioned play audiometry, sound localization test Was conducted for 4-year-old children at 01°,±45°,±90°,±135°and 180°standard positions in the horizontal plane. Results The outcome of sound localization test for 4-year-old children separately were: MAA(0°)=(3.80 4-0.71)°,MAA(-45°)=(7.70±1.27)°,MAA(45°)=(7.10±1.39)°,MAA(-90°)=(8.15±2.38)°,MAA(90°)=(7.61±2.47)°,MAA(-135°)=(8.85±2.70)°,MAA(135°)=(8.30±1.42)°,MAA(180°)=(5.20±1.27)°. The MAA of eight standard positions were less than 10°,and the MAA(0°)was the smallest one. Conclusions Our findings suggest that MAA test procedure on the basis of conditioned play audiometry could be used to evaluate the ability of sound localization in 4-year-old children.