The present study reports the length-weight relationship, relative condition factor of two fish species Trichogaster fasciata (Bloch and Schneider, 1801) and Trichogaster lalius (Hamilton, 1822) of Nitai Beel (wetland) of Kamrup district of Assam. The growth performance of length-weight relationship is found high since the correlation coefficient ‘r’ exhibits high degree of relationship where Trichogaster lalius shows positive allometric correlation and Trichogaster fasciata negative allometric correlation. The positive allometric growth in Trichogaster lalius may be due to higher feeding proficiencies and proper environmental condition whereas the negative allometric growth performance shown by Trichogaster fasciata may be due to lower feeding proficiencies and/or may be due to environmental or seasonal inappropriateness for proper growth of fishes. Interestingly Trichogaster lalius maintains higher degree correlation coefficient and higher value of ‘b’ than Trichogaster fasciata. The Kn value of Trichogaster fasciata is from 0.78 to 1.43 with an average of 1.02±0.08 and Trichogaster lalius from 0.85 to 1.30 with an average of 0.99±0.1 respectively. The relative condition factor are observed to be more or less similar both in numerical value and trend of fluctuation with increasing weight or length of the fish.