measurement of contact angle of powder with hydrophilic and hydrophobic surface by contact angle meter model SL200K series. For hydrophilic surface, drop transferring method cannot be general method and for hydrophobic surface, we may use needle with OD0.2mm to transfer the drop. And we use Young-Laplace equation fitting method for measuring contact angle with hydrophobic surface because in this case, circle fitting method is not suitbale and failure to fitting the drop edge.