This paper tries to elaborate the concept of sale contract in Islamic Fiqh.Presenting Sheik Ansari's analysis about the definition of sale contract, the author discusses that whether the subject of selling should be an object or just any kind of property one owns. He concludes that even if the condition for selling is the objectivity, through differentiating types of objectivity we can consider a wider range of meaning than just its common concept; a range of meaning including all types of possessing, above all ownership.The author then mentions Sheik Ansari's opinion about the price, which notes that the price should not necessarily be objective but can be considered as owning subjective matters as rights, debts and acts. The difference between selling and exchanging, according to Ayatollah Shahid Sadr, is the next part. The last topic is the comparison between selling in Islamic Fiqh and conventional law, referring to the opinions of Abd-al-Razzagh Sanhouri.