One of the main goals for developing the C1 chemical industry is the direct conversion of methane and carbon dioxide to useful products. To realize this goal, researches on new catalytic systems are being globally focused. The exploration has been evolved from traditional heterogeneous catalysis into homogeneous catalysis. Coordinate complexes, biochemical and bionics, and photo- and electrochemical catalysis have been extensively studied in recent years. Tests in laboratories have verified for the direct conversion of CH4 to CH3OH that single-pass converstion of CH4 can reach over 70% in both Hg(Ⅱ) salt and Pt(Ⅱ) complex systems. The main problem of these systems is the obstacles involving reaction kinetics, so they must be solved before moving to pilot tests. Other catalytic systems discussed in the present article include explorations in the early stage. Among them, features of photo and enzymatic catalyst systems, such as mild reaction conditions, better selectivity and environmentally friendliness have been explored, and these researches are significant both in theory and in practical application.