In cloud computing environment there are so many resources, these resources are differ each other in terms of bandwidth, RAM, memory etc. In cloud environment the main objective is how to allocate these resources in an efficient way in order to get minimum or optimal cost. For allocating resources efficiently we need assignment problem and there are various linear programming techniques available to solve this assignment problem. But in day to day life the time or cost for doing task is not real number they are uncertain number. In this paper, to solve this uncertainty problem fuzzy assignment problem associated with fuzzy cost is used. Here fuzzy cost is any trapezoidal or triangular number. Fuzzy assignment problem is solved by row penalty method. This method is implemented on cloudsim simulator and the obtained results are used for allocating resources in cloud environment efficiently in order to get optimal cost and maximum performance.