The paper proposes a two-step quantum secure direct communication (QSDC) protocol using blocks of Einstein-Podolsky-Rosen (EPR) pairs. The protocol involves dividing a set of ordered EPR pairs into two sequences: a checking sequence and a message-coding sequence. After transmitting the checking sequence, the parties check for eavesdropping by measuring a fraction of particles with randomly chosen bases. If the quantum channel is secure, Alice encodes the secret message on the message-coding sequence and sends it to Bob. Bob can read the encoded messages directly by combining the checking and message-coding sequences. The scheme is secure because an eavesdropper cannot obtain both sequences simultaneously. The paper also discusses issues in a noisy channel and proposes experimental setups for realization. The protocol is provably secure in an ideal noiseless channel and conditionally secure in a noisy channel.The paper proposes a two-step quantum secure direct communication (QSDC) protocol using blocks of Einstein-Podolsky-Rosen (EPR) pairs. The protocol involves dividing a set of ordered EPR pairs into two sequences: a checking sequence and a message-coding sequence. After transmitting the checking sequence, the parties check for eavesdropping by measuring a fraction of particles with randomly chosen bases. If the quantum channel is secure, Alice encodes the secret message on the message-coding sequence and sends it to Bob. Bob can read the encoded messages directly by combining the checking and message-coding sequences. The scheme is secure because an eavesdropper cannot obtain both sequences simultaneously. The paper also discusses issues in a noisy channel and proposes experimental setups for realization. The protocol is provably secure in an ideal noiseless channel and conditionally secure in a noisy channel.