Task scheduling is an integrated component of computing. With the emergence of grid and ubiquitous computing, newer challenges have arisen in task scheduling. Unlike traditional parallel computing, grid is a shared enterprising environment where is no central control. The goal of grid task scheduling is to achieve high system throughput and to match the application needs with the available computing resources. This matching of resources in a non-deterministically shared heterogeneous environment leads to concerns on Quality of Service (QoS). The paper presents a novel solution based on Active database to assure Quality of Services in grid computing systems. Active database accommodates some actions to be done automatically by insert, delete or update transactions. In this reason the best matching is obtained by using the most up to date information. Some comparison with other solutions had been done. As a result, our solution is safe factory and acceptable in the limits of performance...