Digital Watermarking enables us to protect ownership rights on digital multimedia, such as audio, image and video data. Digital watermark is a digital signal carrying information of the creator or distributor of the media. Digital watermark is inserted into digital media in such a way that it is imperceptible to the human eye, but it is visible to a computer. A watermarking attack is any processing that may impair watermark detection. There are different types of attacks which can affect the watermarked image which include cropping, noise (salt & pepper, Gaussian), rotation etc. In order to create the copyright issues, these attacks damage the inserted watermark. This paper reviews the performance analysis of the watermarking algorithm based on the combined concept of entropy of block image and LSB Substitution in the presence of different types of attacks to justify the robustness of the algorithm.