Cloud computing is virtual environment that deliver many services and applications via internet. Quality of service (QoS) is one of the main factors that improves the performance of cloud computing. There are various techniques that address improving quality of service, yet there is no clear option that would work more efficient than the other techniques. To ensure quality of service in cloud computing, this research we propose a novel hybrid task scheduling algorithm named (RSDQ) based on tow of shortest-job-first and round robin schedulers using a dynamic variable task quantum considering splitting the ready queue into two sub-queues, Q1, and Q2. Allocating tasks to resources from Q1 or Q2 are done mutually two tasks from Q1 and one task from Q1. The proposed algorithm was implemented in two different environments C# and CloudSim where the experimentations results and tests proved that the proposed algorithm had improved the average waiting and response times and also partially reduced the starvation over the state of art algorithms. Keywords: Cloud Environment, Cloud Computing, Quality-as-a-Service. Load Balancer, Software-as-a-service (SaaS), round robin, shortest job first.