A new density meter was designed and the screw micrometer was used as a volume exchange pump to measure the change of liquid volume. It can measure the volume of 3× 10^-^4ml, and needs only 8mL sample to accurately measure the densities at different temperatures. The meter is very simple, however, it gives a high accuracy, 2×10^-^4g/mL. With this meter, the liquid densities of water, acetone, MIBK and the corresponding binary and ternary mixtures were measured over 293.15- 323.15K.

Key words: WATER, ACETONE, DENSITY MEASUREMENT, TERNARY MIXTURE, PENTANONE, DENSITY