The present technology relates to a transmission device, a transmission method, a reception device, and a reception method which each make it possible to ensure good communication quality in data transmission using an LDPC code. In the present invention, LDPC encoding is performed on the basis of a check matrix of an LDPC code which has a code length N of 1224 or 2448 bits and a code rate r of 252/1224 or 252/2448. The check matrix includes: an A matrix of M1 rows and K columns which is represented by a prescribed value M1 and the information length K=N×r of the LDPC code; a B matrix of M1 rows and M1 columns which has a stepped structure; a Z matrix of M1 rows and N-K-M1 columns which is a zero matrix; a C matrix of N-K-M1 rows and K+M1 columns; and a D matrix of N-K-M1 rows and N-K-M1 columns which is a unit matrix. The A matrix and the C matrix are represented by a check matrix initial value table. The check matrix initial value table is a prescribed table which represents the position of one element of the A matrix and the C matrix every 36 columns. The present technology can be applied to data transmission using an LDPC code, for example.