Investment on construction projects has become an important factor in improving the development of economy in China.The non-price bottom bidding is a representation that the investment on projects is becoming standardized.During the years of trying out the non-price bottom bidding

the colluding in bidding or bidding below the cost has happened several times

which have damaged the benefits of owners.To solve theses problems

this paper firstly studies the reason of these problems-the failure in the normal relationship between principal and agent.Then

some measures have been presented as follows: building systematic and scientific system of qualification prejudication

judging behaviors of colluding in bidding and bidding below the cost with reason and providing a surety mechanism of the project.The authors hope that these measures are beneficial to non-price bottom bidding.