In this paper, we present a fast and efficient Iterative Improvement Partitioning (IIP) technique for VLSI circuits and hybrid bucket structures on its implementation. Due to their time efficiency, IIP algorithms are widely used in VLSI circuit partition. As the performance of these algorithms depends on choices of moving cells, various such methods have been proposed. In particular, the Cluster-Removal algorithm by S. Dutt significantly improved partition quality. We indicate the weaknesses of previous algorithms using a uniform method for the choice of cells during improvement. To solve this problem, we propose a new IIP technique that selects the method for choice of cells according to improvement status and presents hybrid bucket structures for easy implementation.The time complexity of the proposed algorithm is the same as the FM[3] method, and the experimental results on ACM/SIGDA benchmark circuits show improvement up to 33-44%, 45-50% and 10-12% in cutsize over FM[3], LA-3[4] and CLIP[14] respectively. Also with shorter CPU time, our thechnique outperforms Paraboli[10] and MELO[11] represented constructive partition methods by about 12% and 24%, respectively.