Popo Iskandar was a modern painter in Indonesia who worked for 55 years (1943-1998). In addition, he was also a cultural essayist, art observer, educator and writer of art criticism. Judging from the flow of his painting journey, the most important period when he painted cats in the early 1970s by his personal expression. Besides painting cats, he also painted roosters and leopards as his trademark. Through this paper we will analyze the aesthetic value of Popo Iskandar’s works collected by galleries and museums. This research is a qualitative study using the theory of art and function as an expression and method of art criticism. In Indonesia, Andy’s Gallery collects Popo Iskandar’s paint which was created in 1963 with the title Reclining Nude that shows abstract tendencies. The National Gallery of Indonesia collected work in 1977 with abstract and expressionism subject matter. In overseas, Popo Iskandar’s work was collected by the Fukuoka Asian Art Museum, Japan in 1954, entitled Studio with its subject matter is expressionism. The Singapore Art Museum collected works in 1963 with subject matter abstract and expressionism. Next Art Space Washington DC, USA collects a 1990 work with the title is Rooster and cat and the subject matter is expressionism. Based on the results of the analysis, it can be concluded that the works of the Popo Iskandar collection show an expression of Popo Iskandar in seeing subject matter, especially in the subject matter of cats and roosters. The subject matter of the two animals is the idioms of Popo Iskandar himself. The aesthetic value of the work can be seen from the ability to abstract the subject of a painting and visualize it with firm lines that form the object of the painting. Keywords: Popo iskandar, collector, aesthetic value, museum and gallery