Sales transaction on trial use is a sale of special type.Our Contract Law makes the stipulations on it in the first time in Article 170 and Article 171.But those two articles are rather simple and they only involve in periods of trial use and effect on sales transaction on trial use.They have not any explicit stipulations on the risk bear,cost of period of trial use and some other issues,and those are not favorable for the dispute settlement in this field.Therefore they should be perfected.