Abstract: We present a method for construction of LDPC codes with 2-column weight. This method is based on graph. By considering a LDPC code, we can construct a 2-column weight LDPC code. In this method, we obtain a parity check matrix mxn from a parity check matrix with m rows and n columns for a LDPC code. The girth g in initial check matrix increases to 2g in new check matrix. This increasing is effective in decoding of code. From the simulation result, we observe that the new LDPC code has better performance than Mackay and nil codes in the field Fq.