We agreed that something had to be done to promote the popularity of local films, some of them being great works of art.

works 是名词 work 的复数形式。work 在这里指"作品"，特别指艺术创作或文学创作等智力劳动的产物。 great works of art 指"伟大的艺术作品"，强调这些电影具有很高的艺术价值。