To explore a method for detecting solids content of soybean milk, network analyzer and openended coaxialline probe were applied to study the influence of frequency (20~4500MHz), temperature (20~80℃) and solid content (2.00~7.01g/（100mL）) on dielectric parameters (relative dielectric constant ε′ and dielectric loss factor ε″) of soybean milk. The models describing the permittivities as functions of temperature and solid content were built, and its feasibility to predict solid content using obtained permittivities were verified. The results showed that over the frequency range of 20~4500MHz, ε′ was decreased with an increase of frequency, and ε″ was increased after decrease with increasing frequency. The minimum ε″ was observed at 600~2000MHz. ε′ was decreased with an increase of temperature, and ε″ was increased with increasing temperature at low frequency end and decreased at high frequency end. The frequency where minimum ε″ was increased with increasing temperature. ε′ was decreased but ε″ was increased with increasing solid content. At a given frequency, quadratic polynomial could be used to describe the relationship among permittivities (ε′ and ε″) and temperature and solid content. The determination coefficient of the built model was 0.989 for ε′ (100MHz) and 0.990 for ε″ (20MHz). The model verification results showed that the determination coefficient was 0.978 between the calculated solid content using obtained ε″ at 20MHz and the measured ones. This study indicated that permittivities could be used to detect the solid contents of soybean milk.