In this paper, a new constant rate solution for asymmetrically fractured wells was proposed to analyze the effect of fracture asymmetry on type curves. Calculative results showed that for a small wellbore storage coefficient or for the low fracture conductivity, the effect of fracture asymmetry on early flow was very strong. The existence of the fracture asymmetry would cause bigger pressure depletion and make the starting time of linear flow occur earlier. Then, new type curves were established for different fracture asymmetry factor and different fracture conductivity. It was shown that a bigger fracture asymmetry factor and low fracture conductivity would prolong the time of wellbore storage effects. Therefore, to reduce wellbore storage effects, it was essential to keep higher fracture conductivity and fracture symmetry during the hydraulic fracturing design. Finally, a case example is performed to demonstrate the methodology of new type curves analysis and its validation for calculating important formation parameters.