Change effort is complex process. If it should be really effective, some intangible part such as culture and value of client system should be modified. But there are obvious barriers which jeopardize the whole process. Working as outside contractor, from beginning of the change management program, consultant tends to solve problem that can easily measured. All this happened because of commercial interest of consulting project: must be finished according to project cost, timing and client satisfaction. How can make client feel satisfactory? The easy way is only to solve problem that client can measured and feel. During the feedback period，consultant always chose some topic that already change client system but feel reluctant to face tough aspect of change process. The trick play by consultant is shifting some of the responsibility to client and tells client that the system is unsuitable at present to change. So the feedback process is harm by the commercial process. As change effects emerging lag behind the change effort, during the evaluation period, manifestation and measurement effects of is out of question, this makes consultants at lose to deal with and frustrated client. In order to prove the effectiveness of change program, some financial indexes are chosen as the measurement. But this kind of measurement is infected by wide scope of factors, which lose reliability of measurements and led to wrong way of evaluation. As the measurement lose reliability, no one can draw conclusion that change management program succeed or not even consultant himself. Some survey results reveal that most organizations rely on financial, operational and customer service metrics to evaluate the success of change efforts, that success is highly correlated with visible support from a change sponsor, that failure is associated with missing or conflicted leadership, and made change effort success or lose at no reason. Working as outside contractor, consultant and consulting firm should carefully design and openly change ideas with client to avoid risk concerning whole change management program and make both client and consulting firm better off.