Abstract: An experiment was conducted at the Agronomy Field Laboratory, Bangladesh Agricultural University, Mymensingh during the period from May to November 1998 to investigate the effect of green manures and different levels of nitrogen on tillering behaviour, dry matter production and yield of transplant aman rice (cv. BRRI dhan32). The experiment was laid out in a randomized complete block design with three replications. The experiment comprised of 3 green manuring crops viz., Sesbania rostrata, Sesbania aculeata and Crotalaria juncea and 5 levels of N viz., 0, 20, 40, 60 and 80 kg ha-1. Dry matter production was increased with the age of the plant and also increasing trend was observed irrespective of green manuring crops in combination with higher levels of nitrogen, but number of tillers hill-1 increased up to 67 days after transplantation. The highest dry matter production and the highest number of tillers hill-1 were obtained with the incorporation of S. rostrata in combination with 80 kg N ha-1. S. aculeata also exhibited similar behaviour in these regards. The highest number of effective tillers hill-1 and the highest grain yield were obtained with Sesbania spp. in combination with 40 kg N ha-1 but C. juncea showed comparatively poor performance in respect of the aforesaid parameters due to less amount of biomass added during incorporation.