A d-dimensional unit of information in quantum computing is called a qudit. For d = 4 there exist four magnetic quantum numbers of spin-3/2. These four levels can be called ququarts. Then, for the SI (S = 3/2, I = 3/2) spin system, 16 two-ququart states are obtained. In this study, first, two-ququart entangled states are constructed by using matrix representation of Hadamard and CNOT logic gates. Two-ququart entangled states are also constructed by using magnetic resonance selective pulse sequences of Hadamard and CNOT logic gates. Then, a generalised expression is obtained for the transformation of two-qudit entangled states between each other. This expression is applied for two-ququart entangled states.