On the basis of the models adopted by Heckmann in 1925 and Thurston in 1994 describing physical effects in crystals, the first author established an expanded model at the beginning of 1999 describing the physical effects involving conversions among mechanical, electric, thermal and magnetic energies. In this thesis the authors investigate further to establish a more complete model endeavoring to include and explain the numerous physical effects of crystals explicitly. The principal effects and the coupled effects are illustrated in diagrams and expressions have been deduced analytically with the help of the thermodynamic method. A general expression for concerning physical effects in crystals is reached which can be seen as a natural deduction fron Onsager's theory. The new model will be helpful in the understanding of knowledge on physical effects and will be of great significance in investigations on sensors, actuators and senactuators.