Abstract: There are many merits for focused liquid-filled spherical reflectors:email geometric size, high target strength, excellent frequency property, homogeneous directivity, low cost and easily placed in the sea. At present, the focused liquid-filled spherical reflector is a better type of all standard reflectors." This paper presents some experimental results of focused liquid-filled spherical reflector in the frequency range 120-460 kHz. The problem of raising the focusing gain in changing temperature is investigated besides the relation between target strength and frequency, directivity and index of refraction. Maximum focusing gain is obtained by choosing proper proportion of liquids at different temperature. The maximum focusing gain can reach 23 decibels.