A plate structure is of key interest to aerospace, mechanical and civil engineers. Vibration reduction is a major challenge pertaining to these fields; especially in aerospace applications, such a reduction must be achieved with a minimal increase in weight. The vibration of plates is a special case of the more general problem of mechanical vibrations. In this paper effect of bi-parabolic variation in temperature is premeditated on vibration of an orthotropic rectangular plate and whose thickness also varies bi-linear as in two dimensional. Frequency equation is derived by using Rayleigh-Ritz technique with a two-term deflection function. Time period, Deflection and Logarithmic decrement at different points for the first two modes of vibration are calculated for various values of thermal gradients, aspect ratio and taper constants
