AbstractThis paper proposes and describes a new cut torsional quartz resonator which is designated “TT‐Cut,” and clarifies its frequency characteristics, frequency temperature behavior, and electrical equivalent circuit parameters.First, in the analysis procedure, an equation of motion is derived from an energy method. Next, by solving the equation of motion under the boundary conditions of “free‐free bar” or “clamped‐free bar,” the frequency equations are derived as a function of thickness z0, width x0, and length y0.Furthermore, from the frequency equation a relationship of frequency constant (f. y0) versus thickness‐to‐width ratio Rzx (= z0/x0) and a relationship between thickness‐to‐width ratio Rzx and cut angles (ϕ, θ) where the first‐order temperature coefficient α reaches zero are derived theoretically. As a result, numerous relationships where α reaches zero are found to exist between thickness‐to‐width ratio Rzx and cut angles (ϕ, θ). Especially, the second‐order temperature coefficient β has a small value of ‐1.16 × 10−8/°C2 whose absolute value is approximately one‐third of the well‐known flexural mode quartz crystal resonator. The value of β then is‐compared with the measured data of ‐1.29 × 10−8/°C2, so that both results are found to agree sufficiently well.Finally, series resistance R1 and a quality factor Q of a tuning‐fork‐type resonator are examined. Consequently, it is shown that a tuning‐fork‐type torsional quartz crystal resonator is obtained with a small R1 of 2.2 to 14.4 k° and a large Q value of 276, 000 to 378, 000 in frequency range of 385 to 444 kHz.