Since Pratuang became a free-lance artist, his style has undergone several developments. In the beginning, he was motivated by personal and social affairs, as well as violent events of the world, especially wars which brought about human grief and problems. He paid special attention to these issues because he believed that art must benefit society, redeem people by reflecting their mistakes, and guide them towards what was right. Such was the subject matter of his early works which were accomplished in modern art forms.

After several years of apprenticeship with Nature, he began to realize the essence and value of Nature. He became happier and more optimistic with a strong faith in virtue which he believed to be intrinsic essence of Life. He created a style of his own by merging what he perceived from Nature with what he had within himself. the style was independent of all academic conditions and was not under any artist's theories. His methods of expression, free and unique, revealed his feelings through bright colors and bold lines, expressive of the energetic might and beauty of Nature. His paintings created during that period were collectively called "The Universe Series" because the general theme concerns components of universal phenomena, including the Sun, the Moon, and the stars. His style emerged and became distinct from then on.

After the Universe Series, which belongs to the category of "naturalism", Pratuang went on to "symbolism" or "abstract art" The rich, bountiful, and interrelated features of Nature, i.e.' land, sunshine, streams, trees, mountains etc. were digested and impressed into simple, free forms, such as circles and ellipses, that appeared vivid, lively, and forceful. The abstract trend has had influence on his works up to now.

Then came two momentous political events which occurred on October 14, 1973 and October 6, 1976 respectively. The former resulted in a change in government system, from military regime to democracy. Freedom of expression was then encouraged, including criticism on culture and art. These arose then a new attitude in the Thai artists' circle that true art must be "for Life's Sake" not "for Art's Sake" as it was formerly believed. All these changes inevitably had an effect on Pratuang's style. His works became more realistic, depicting components and essence of the common people, such as farmers, ploughs, paddy, huts etc. Then came the bloody events of October 6, 1976, which motivated Pratuang to create an enormous painting, recording the historic day ---'The Day of the National Sorrow.'

After the political tumult died down, the subject matter of his artistic works returned to Nature. With full realization of the essence and virtue of Nature, his style changed once again and has remained so ever since. It is now freer and more direct, without having to express through physical forms. Before doing a work of art, he usually travels to the countryside to spend a peaceful life among the fields, the hills or the sea and absorb  the energy of life which fills the earth, the seeds, the sunlight, the winds, and the seemingly vacant space of the air. The energy evolves with the seasons, mingles with the gentle mist, and emerges from the petals and pollen of the flowers. It is part of the integrity of Nature. From Nature, Pratuang gains strength and freedom of spirit. He will then express his joyous feelings thought compositions of lively colors and forceful lines. He believes that the virtue in human mind correlates with that in Nature. Only when an artist at work has abandoned all attachments, and purged his mind of all impurities, can be completely translate the quality of Nature into his work.